Is the odour caused by bacteria on the skin?? or is it coming from inside - by this I mean is it a gas leaving your system via your feet?? I have overactive sweat glands in my feet and over the years I have felt that a gas comes out bringing a smell like sewage. Some people can get odours coming from different parts of their bodies such as the chest, stomach area, hands, feet, and head.
I believe internal candida can cause your feet to smell, so you could have a yeast overgrowth in your system.
If the cause is external, such as bacteria on the feet, the posts below might help you:
Have you tried washing your feet in the cleansing solution used by surgeons before an op. You can buy this on-line for a few pounds - one supplier is VIRUSafe. This should kill all bacteria and fungus on skin.
Also, have you seen this post:
My podiatrist helped me control my foot odor by soaking my feet about 15 minutes in an Epson Salts bath (1/2 cup of Epson Salts in 1/2 gallon of luke warm water). At the time, the heels of my feet had alot of little cracks in them, and she prescribed Kerol Redi-Cloths (42% urea). She told me that bacteria was growing inside the little cracks in the heel of my feet.
The Kerol Redi-Cloths are very expensive (prescription strength urea), but my insurance covered it. I guess you could also try to get a prescription for just the urea 42% and any foot scraper would do. One side of the cloths helps scrape off dead skin and the other side has the urea that you apply all over each foot. It's best to scrape gently scrape the soles of your feet after soaking them in a Epson Salts bath or after showering.
She recommended that I use socks and closed shoes during this treatment. She recommended I put a bactericidal foot treatment called On Your Toes (Bactericide USP purified microfined oxide of zinc) powder inside my shoes to help kill the bacteria that may have grown, or may grow inside my shoe. I bought new shoes after having begun this treatment to make sure I didn't re-contaminate my feet again.
This was a couple of years ago, and I haven't had foot odor since.
If you cannot get redi-cloths you can try Ped-Egg to take off hard skin, and you can google for 40% urea - I think there are only a couple available at this strength that you do not need a prescription for.
Also try Eradicil when washing socks, towels and bed linen as this apparently kills bacteria and fungus and prevents re-infection.
One other option is to see a Chinese heralist, as they can sometimes help.