text: See what bacteria are on your hands after you wash them with different kinds of soap versus just rinsing them with water.  The trick is getting the starting point to be the same.  I think what you'd need to do is wipe your hands down with alcohol and have a source of bacteria (a piece of raw chicken could work) that you rub your hands on each time.  I would imagine something like: rinse your hands with ethanol (to kill whatever is already there), touch the bacteria source, wipe your fingers on a control plate (if you don't have proper aguar plates, you can use chicken broth as per the experiment above), wash your hands with the soap to be tested, and wipe your hands on another plate.  Rinse your hands with enthanol again and repeat for other soaps and plain water.  Leave the samples to grow overnight (or longer) and compare the bacteria growth on the different plates.\n\n___________________\nI just thought of another experiment that could be really cool... Leave your plates (or chicken broth, or whatever) out in the air for a while, so they get both mold and bacteria growing on them.  Let them grow for a while, and observe the locations of bacteria in relation to mold.  That's how Alexander Flemming discovered penicillin!