A challenge: Talk to a professor of microbiology about how clean or dirty the average home may be, and count how many times he throws out the phrase “traces of fecal matter.” Sufficiently disgusted yet? Wait until you hear more from Charles Gerba, Ph. D., Professor of Microbiology & Environmental Sciences at the University of Arizona College of Public Health, and cleaning expert extraordinaire Jolie Kerr. We asked them to share their vast expertise about the world of germs, then promptly set off to buy industrial-sized vats of every cleaning agent ever invented. Read on, and you’ll want to thank the person who brought bleach spray bottles and sanitizing wipes into existence.