Steve, Dubai asked:
What is it in soap that kills all the nasties?
Soap is a very good way of cleaning your hands because its got oily molecules in it that will break down the membranes of microorganisms. All microorganisms are surrounded by an oily bag which separates the good things inside a cell from the environment outside. And because itís oily, if youíve got some detergent or soap it can stick its wiggly chain into that oily bag, break it open and then bust open the bug. This is why soap actually works and detergents work. Physically rubbing your hands together also helps, as it detaches microorganisms when under a stream of water.