Hello, Smelly feet are usually due to growth of bacteria on the skin of the feet which acts on sweat and produces the stink. Regularly cleaning his feet,keeping shoes and socks dry, keeping 2 pairs of shoes and wearing them alternatively are few basics to help with the same. If none of the home remedies which are usually available on the web is working, then you can try antibacterial soaps like Hibiscrub. We also recommend dipping feet in warm water mixed with Eusol solution if none of the above work. This is a common problem among teenagers due to their hormonal changes. Other reason for this might be a condition where one sweats excessively which has to be seen and diagnosed by a doctor in person. I hope I answered your question satisfactorily. Thank you.