remedy for extreme foot oder

Hi all, I am looking for some kind of remedy that I can buy or make for my husbands feet. He has an extreme fungil thing going on and the smell is horrific!!! I have been dealing with this for 22 years now. He soaks his feet in bleach to kill the smell. It stays gone until he has his feet in shoes again. I know that soaking in bleach water is toxic and want him to stop doing it. any info will be much appreciated. Thanks!!