answer:I don’t know the mechanism for why it works, but I do know it doesn’t matter what kind of vinegar you use. If you have mildewed or moldy clothes, vinegar does a great job of killing the smell, so I think that your answer would be that mildew, mold, ringworm, and fungal infections on feet cannot live in an acidic environment. My daughter lives in Japan. She had exactly the same problem as you do. In addition, she was allergic to the cream she was using, and by the time she realized it, she was bleeding in places! I told her to buy the cheapest vinegar she could find (which was a rice **** vinegar), and soak her feet in a weak solution of vinegar and water several times a day. It started to get better immediately, and as it healed, she increased the amount of vinegar in the water. She always keeps a bottle of cheap vinegar on hand now for athelete’s foot