Gentain Violet as I understand is supposed to kill any fungus ect in 30 day maximum. I found ten days for ringworm looking stuff to work most of the time. I live in the Fl. so I've had a lot of experience strange skin conditions and gentain violet. I hate going around with purple spot, but it beats having whatever your putting it on. Anyway once the skin is no longer infected it washes away in a few days. Works better for me than the big pharma fungucides. Good luck!