Some folks use a little hydrogen peroxide in the water - others use a tiny drop or two of regular bleach - this is for stuff like grapes, strawberries and such fruits that can't be scrubbed. I just use warm water and a scrub brush on most things like apples and oranges, squash and the like. I also soak lettuce, greens and such in cold salt water. That salt will kill off "nasties" too.