Jock itch doesn't come out of nowhere. I got it last year for the first time. I treated it, it was gone in about 2 weeks, and it hasn't come back. You need the fungal spores there for it to develop, not the bacteria that's naturally hanging around. I still don't think sanitizing will help; for one thing, I doubt anything you could spray on the fabric could kill the spores AND not be like acid on your own skin. After all, if there was such a spray, you could use it directly ON your skin to cure the fungus, and there isn't such a thing. My doctor said the ONLY way to kill the fungus is to get it when it's reproducing, that's when the antifungals act on it. If it's in its spore state, which it would be on the clothing, you could soak them in alcohol and it wouldn't kill them.