I vaguely remember reading something about a study where they used some sort of UV dye or something to represent contamination. They then compared how well clean freaks and normal people did at preventing the spread of contamination in their kitchens (such as from raw poultry). It turns out that the clean freaks did much worse because they wiped lots of things down without really cleaning them and whatnot and thus spread the contamination all over.
You should put some UV dye on your hands and do stuff that spreads it around like pass out handouts, at the end you could bring out a UV light and show how you covered half the room, heh.