FOR THOSE OF YOU WITH STRONG MUSTY SMELL ONLY IN WASHCLOTHS, it's from washing off underarm odor. It's worse if you just "wash up" sometimes without actually showering because then you don't really rinse out the washcloth as well as you do in a shower. The smell is darn near impossible to get out unless you use borax or clorox 2. Ammonia and baking soda didn't work. ... View related article.