I know I can just wash my hands and be clean enough to handle food! It's my job after all. This actually isn't the first time I've been challenged by someone quoting all kinds of irrelevant scientific concepts: once I said you can wash veg in cold tap water (which is true where we live!) and this young squirt piped up going on about stillwater, breaking surface tension, bacteria... the knowledge apparently isn't worth much without real world experience!