Baby Wipes.

"Burning Man, children, is about sex, drugs, music, and baby wipes." -Don Farwell

Mess is one thing. If you have your crap all over your home because you actively use it as a living space, then good for you. Letting the grime and filth accumulate, however, is nasty and you need to clean that shit up. If a million people raging in the desert-drunk, high, dehydrated, sweaty, covered in playa dust- can keep themselves and their camp clean, so can you.