How to Clean Insoles of Smelly Shoes (And Whiten Soles): 2026 Expert Guide

Introduction

If there is one universal truth I’ve learned after spending over 20 years managing a footwear business and handling thousands of pairs of shoes, it’s this: feet sweat. In fact, the average foot has roughly 250,000 sweat glands and can produce up to half a pint of moisture a day.

While most people focus on keeping the outside of their sneakers or boots looking fresh, the inside—specifically the insole—is where the real battle happens. That moisture, trapped in a dark, warm environment, becomes a breeding ground for bacteria and fungi. This isn’t just a hygiene issue; it destroys the materials of your footwear from the inside out.

Whether you are a daily commuter in London, a hiker in Colorado, or someone navigating the humid streets where my physical shop is based, the result is the same: smelly shoes that feel damp and uncomfortable.

In this guide, we are going deep into shoe care. We aren’t just covering how to clean insoles of smelly shoes; we are looking at specific materials like Birkenstock footbeds, memory foam, and even how to whiten yellowing soles.

Quick Answer: How to Clean Insoles?

For removable fabric or foam insoles: Mix warm water with a mild detergent (dish soap or laundry detergent). Scrub the insole gently with a soft-bristle brush. Rinse with a damp cloth (do not soak) and air dry completely away from direct heat. For odors: Sprinkle baking soda over the dry insole, leave overnight, and shake off. For leather/Birkenstocks: Use a damp cloth with a 50/50 vinegar-water solution; never submerge in water.

Why This Topic Matters (The “Invisible” Problem)

In my two decades of retail experience, I’ve seen countless customers throw away perfectly good shoes simply because they couldn’t get rid of a bad smell or the footbed felt “grimy.”

The mistake most buyers make globally is treating the shoe as a single unit. They throw the whole sneaker in the washing machine. Do not do this. Machine washing can warp the structural heel counter, dissolve water-based glues, and ruin the cushioning properties of EVA (Ethylene Vinyl Acetate) midsoles.

By learning how to clean the insole separately, you extend the lifespan of your footwear, save money, and maintain better foot health. It is the difference between a shoe that lasts six months and one that lasts three years.

Understanding Your Insole Material

Before we start scrubbing, we need to identify what we are working with. As a retailer, I categorize insoles into three main types found in the global market:

1. Removable Foam/Fabric: Common in running shoes (Nike, Adidas, Asics) and casual sneakers. Usually made of EVA or PU (Polyurethane) with a fabric top sheet.
2. Fixed/Glued Leather or Suede: Common in dress shoes, high-end boots, and sandals like Birkenstocks.
3. High-Tech Memory Foam: Found in Skechers and comfort walking shoes. These act like sponges and require very delicate handling.

Method 1: The Deep Clean (For Removable Fabric Insoles)

This is the standard method for 90% of athletic and casual footwear.

What You Need:

• Mild liquid detergent or dish soap.
• A soft-bristle brush (an old toothbrush works perfectly).
• A towel.
• Warm water.

The Step-by-Step Process:

1. Remove: Take the insoles out of the shoes. If they are glued slightly, don’t force them—skip to the “Fixed Insole” method.
2. Dry Brush: Use the dry brush to remove loose lint, sand, and sock fuzz.
3. The Mix: Create a soapy solution with warm water.
4. Scrub: Dip the brush in the solution and scrub the fabric top layer in circular motions. Focus on the heel and toe areas where sweat accumulates most.
5. Rinse (The Right Way): Do not hold them under a running tap like a dish. The foam can absorb too much water and take days to dry. Instead, wipe the soap away with a clean, wet sponge or cloth.
6. Air Dry: Pat them down with a dry towel to absorb excess moisture. Place them in a well-ventilated area.

Expert Warning: Never place insoles on a radiator or in a dryer. The heat will shrink the foam, curling the edges. Once an insole curls, it will never fit comfortably in your shoe again.

Method 2: How to Clean Birkenstock Insoles (Suede & Cork)

One of the most frequent questions I get is how to clean Birkenstock insole footbeds. The dark footprint stain is natural (it’s oils from your foot reacting with the leather), but when it gets shiny or smelly, it needs attention.

The Golden Rule: Cork and water are enemies. If the cork gets saturated, it cracks.

The Vinegar Method:

1. Brush: Use a suede brush to nap up the leather fibers.
2. Solution: Mix equal parts white vinegar and water.
3. Wipe: Dip a cloth into the solution (wring it out well so it’s just damp) and scrub the footbed. The acidity in vinegar kills bacteria and breaks down grime without damaging the leather.
4. Dry: Dry slowly in the shade.

The Sandpaper Trick (Retailer Secret):

If the suede liner is extremely matted, dark, and shiny, use a block of fine-grit sandpaper. Gently sand the top layer of the footbed. This physically removes the dirty layer and exposes fresh, soft suede underneath. This brings the “grip” back to the sandal.

Method 3: Odor Elimination (The “Stink Bomb” Protocol)

Sometimes, cleanliness isn’t the issue—it’s the smell. If you are searching for how to clean insole of shoes because of a persistent odor, washing might not be enough. You need to neutralize the pH.

Baking Soda Strategy:

1. Ensure the insole is bone dry.
2. Put the insoles in a Ziploc bag or a shoebox.
3. Cover them generously with baking soda.
4. Add a few drops of essential oil (Tea Tree is best as it is antibacterial) if you have it.
5. Seal the container and leave it for 24 hours.
6. Shake off the powder. The baking soda absorbs the moisture and neutralizes the acid in the sweat that causes the smell.

Method 4: How to Whiten Shoe Soles

While we are cleaning the inside, we often look at the outside and see that the crisp white rubber has turned yellow. This isn’t dirt; it’s oxidation.

If you want to whiten shoe soles, soap won’t work. You need a chemical reaction to reverse the oxidation.

The Hydrogen Peroxide Method:

1. Clean: Wash dirt off the sole with soap and water.
2. Apply: Buy “40 Volume Creme Developer” (used for hair bleaching) or a dedicated “Sole Sauce.”
3. Paint: Apply the cream to the yellowed rubber parts carefully. Avoid the fabric upper!
4. Wrap: Wrap the shoe in clear plastic wrap (cling film) to keep the moisture in.
5. UV Exposure: Place the shoes in direct sunlight for 1 to 3 hours. The UV light activates the peroxide, reversing the yellowing.
6. Rinse: Wash off the cream thoroughly.

Pro-Tip Section (Insider Retailer Insights)

After years of fitting shoes, here are the things strictly between us experts that most brands won’t tell you on the box.

• The “Tea Bag” Hack: If you are traveling and don’t have baking soda, place dry, unused black tea bags inside your shoes overnight. The tannins in the tea kill bacteria and absorb moisture.
• Rotation is Key: It takes 24 to 48 hours for the foam in your insole to fully decompress and dry out after a long day. If you wear the same pair every single day, you are compressing damp foam, which accelerates bacterial growth. Rotate between two pairs.
• The Size Factor: Many people buy shoes that are slightly too tight. This increases friction and heat, leading to more sweat. A proper fit (with a thumb’s width at the toe) allows air circulation, reducing odor build-up.

Comparison: Choosing the Right Cleaning Agent

Not all cleaners are equal. Here is a quick breakdown of what to use based on your problem.

Common Mistakes to Avoid

1. The Washing Machine: I cannot stress this enough. The agitation cycle tears at the mesh and the water saturation ruins the density of the insole foam.
2. Using Heater Vents: Drying your shoes on a heater creates a humid, warm environment perfect for mold, or it dries the leather so fast it cracks.
3. Ignoring the Socks: Cleaning your insoles is useless if you are wearing synthetic, non-breathable socks. Switch to cotton or merino wool blends to reduce the sweat reaching the insole.

People Also Ask (PAA)

Can I wash my shoe insoles in the washing machine? Generally, no. The agitation can shred the fabric lining and water saturation can ruin the foam structure. Hand washing is always safer.

How often should you wash shoe insoles? For daily wear shoes, aim for once every two weeks. For running shoes, you should air them out after every run and wash them monthly.

Does rubbing alcohol clean smelly shoes? Yes. You can spray a 70% isopropyl alcohol solution into shoes to kill bacteria immediately, but let it dry completely before wearing.

Can I replace the insole instead of cleaning it? Absolutely. If the foam is compressed or permanently smelly, replacing them with aftermarket insoles (like Superfeet or Dr. Scholl’s) is an upgrade for your feet.

Why do my Birkenstocks smell? Birkenstocks absorb sweat into the cork and suede. Without regular airing out and vinegar cleaning, this trapped moisture breeds bacteria.

Conclusion & Next Steps

Cleaning your insoles is a small habit that yields massive results. Your shoes will last longer, smell better, and provide better support. Whether you are scrubbing a muddy sneaker or carefully restoring a Birkenstock, the effort is worth it.

If your insoles are beyond saving—compressed to the thickness of paper or falling apart—cleaning won’t help. It might be time to look for a replacement or a new pair of shoes entirely.

Ready to upgrade your comfort?

• [Check today’s best-rated moisture-wicking insoles on Amazon]
• [Browse top-reviewed breathable walking shoes]
• [See the best shoe care kits for sneakerheads]

FAQs

1. How do you deep clean non-removable insoles? Use a damp cloth with soapy water and scrub gently inside the shoe. Do not soak the shoe. Use a toothbrush for tight corners and stuff with paper towels to dry.
2. What kills the bacteria in shoes? UV light (sunshine), freezing temperatures (freezer method), vinegar, rubbing alcohol, and specialized antifungal sprays are effective at killing bacteria.
3. Does freezing shoes kill the smell? It is a temporary fix. Freezing puts bacteria in a dormant state. Once the shoe warms up and you sweat again, the smell usually returns.
4. How to clean memory foam insoles? Be very gentle. Memory foam acts like a sponge. Wipe with a damp cloth; do not submerge, as they take days to dry and can grow mold if the core stays wet.
5. Can I use baking soda and vinegar together on shoes? Yes, but be prepared for the fizz. The reaction helps lift dirt, but it can be messy. It is better to use vinegar for cleaning and baking soda for drying/deodorizing.
6. How to dry insoles fast? Use a fan or a hair dryer on the cool setting. Never use hot air. Stuffing the shoes with newspaper also helps wick moisture away quickly.
7. Why do my shoes smell even after washing? The bacteria might have penetrated deep into the midsole or the upper material. You may need an enzymatic cleaner designed to eat the bacteria, not just mask the smell.
8. How do I keep my Birkenstocks from smelling? Apply a suede protector spray when they are new. Wipe them down after heavy sweating and never wear them two days in a row to allow them to dry.
9. Is hydrogen peroxide safe for shoe insoles? It is safe for white synthetic insoles but can bleach colored fabrics. Use it primarily for whitening rubber soles or disinfecting white interiors.
10. What is the best homemade shoe deodorizer? A mixture of baking soda, cornstarch, and a few drops of essential oil (lavender or tea tree) creates a powerful, natural deodorizing powder.