Insoles are why shoes smell, and almost nobody washes them. People clean the outside of a shoe, spray the inside, and replace the whole pair when the smell wins, having never touched the one component that holds most of the problem.
Where the smell actually comes from
Feet have a very high concentration of sweat glands, and a pair of them produces a surprising volume of moisture over a day.
Sweat itself is close to odourless. The smell is produced by bacteria feeding on it, and specifically by the compounds they release, which is why the problem is biological rather than a matter of dirt.
Those bacteria need warmth, moisture, and something to feed on. A closed shoe supplies all three, and the insole is where the moisture actually collects, because it sits directly under the foot and absorbs downward.
A foam or fabric insole is a sponge that has been holding sweat and skin cells for months. Spraying the shoe cavity does nothing to what is inside that sponge.
Take the insoles out first
Most insoles lift straight out, and a great many people have never checked.
Removing them does three things at once. It lets you clean the item holding most of the problem. It lets the shoe interior dry properly, which it cannot do with an insole in place. And it lets you see whether the insole is compressed and finished, which is a separate issue from smell.
If they are glued in, the shoe has to be dried and treated as a whole, which is slower and less effective.
Washing insoles
Hand washing is right, and it takes a few minutes.
Brush off loose debris first with a dry brush.
Wash in warm water with a small amount of enzyme detergent, working it in with a soft brush on both faces. Enzymes matter here specifically, because you are dealing with protein and body oil rather than dirt, and that is exactly what they break down.
For anything that already smells, soak first in cool water with a cup of white vinegar for half an hour. Vinegar handles the alkaline compounds bacteria produce, and it does more than detergent alone on established odour.
Rinse thoroughly. Detergent left in foam holds odour rather than removing it, which is the same trap as with towels.
Press the water out between towels. Never wring, which crushes and creases the foam permanently.
Never a washing machine for foam or gel insoles, where the agitation and spin break down the cell structure.
Drying, which is the whole thing
Air dry, completely, and expect it to take a day or more for a thick foam insole.
Never a dryer, a radiator, or direct sun. Heat warps and hardens foam, delaminates layers, and can shrink a fabric top cover so it no longer fits the shoe.
Stand them on edge so air reaches both faces, with a fan on them if you want it faster.
Put them back only when they are genuinely dry through. A damp insole returned to a shoe puts you back where you started within a day, because you have restored the exact conditions the bacteria need.
This is the step that decides whether the work holds.
The shoes themselves
With the insoles out, the shoe cavity can finally dry.
Stuff them loosely with newspaper or a cloth, which draws moisture out of the lining, and change it after a few hours.
Wipe the interior with a cloth dampened with a vinegar solution and let it dry fully.
Bicarbonate of soda left in overnight and shaken out absorbs a good deal of residual odour.
For canvas trainers, a cold gentle machine wash in a mesh bag with the laces and insoles removed is usually fine, air dried and never tumbled. Leather and structured shoes should not be immersed.
Socks are half the problem
Insoles get most of the blame and socks deserve a share of it.
Synthetic socks hold body oil, and oil held against the foot feeds the same bacteria. Wash socks warm rather than cold with an enzyme detergent, turned inside out.
Change socks daily without exception, and twice on a hot day.
Merino wool socks are genuinely better here, because wool absorbs moisture into the fibre where bacteria cannot easily reach it and it is mildly antibacterial.
Never put a foot into a shoe that is still damp from yesterday.
The rotation that fixes it for good
The single most effective habit is owning two pairs and alternating them.
A shoe needs about 24 hours to dry out fully, and a shoe worn daily never gets that. Alternating gives each pair a full day to dry, which breaks the cycle without any product at all.
Two pairs alternated also last considerably longer than two pairs worn consecutively, so it costs nothing over time.
Keep a second set of insoles as well, which is cheap and lets you swap while a pair dries.
When to replace an insole
Insoles have a shorter life than the shoes they sit in.
Replace them when the foam feels compressed and no longer springs back, which is the main failure and the least noticed.
Replace them when the top cover has worn through at the heel or the ball.
Replace them when the smell returns within days of a proper wash and dry, which means the foam has been colonised right through.
Replacement insoles cost a fraction of new shoes and they restore both the cushioning and the smell situation at once.
The Tustin part
Two local conditions matter here.
The warm dry climate cuts both ways. Southern California warmth means more sweat over more of the year, and shoes worn without socks, which is common here, put foot oil directly into the insole with nothing absorbing it first. That accelerates the problem considerably, and it is the strongest argument for washing insoles seasonally rather than never.
The dry air is the compensating advantage and it is a large one. Insoles and shoes air dry here in hours rather than days, which makes the rotation habit genuinely easy and removes the temptation to speed drying with heat. A shaded patio or a spot with airflow does the job overnight.
Coastal humidity is a third factor for anyone nearer the water, where morning damp slows drying and a shoe left in a closed car or a gym bag stays wet. That is the worst case for odour, and it argues for taking shoes out of a bag as soon as you get home rather than the next morning.
Where the socks and gym kit go
Insoles stay out of a machine, and the socks and athletic kit that are half the problem do not. Getting body oil out of synthetic sock yarn takes warm water, an enzyme detergent, and enough water volume to carry the oil away rather than redistribute it.
The machines at our self-service laundry on East 1st run full warm cycles with real water volume, which is what removes oil from synthetics rather than moving it around the drum.
Our machines and the store are cleaned daily.
Nou wash-dry-fold service covers the everyday laundry.
For general washing guidance, The American Cleaning Institute publishes a laundry basics guide that is a useful cross-check.
The short version
Insoles hold most of the moisture and most of the bacteria, so spraying the inside of a shoe treats the wrong thing. Take them out, soak anything smelly in cool water with vinegar, then wash warm with an enzyme detergent and rinse thoroughly. Press dry between towels and air dry completely, which takes a day, and never use heat, which warps foam. Put them back only when genuinely dry, or you restore the exact conditions the bacteria need. Wash socks warm with enzymes, and alternate two pairs of shoes so each gets 24 hours to dry.
WaveMAX Tustin is at 412 E 1st St, easy to reach from Tustin and the surrounding area. For the socks and gym kit, call us at 855-492-8362.