Paper or water?

From The Big Necessity: "In toilet customs, the world divides, roughly speaking, into wet (flush) or dry (no flush). In anal-cleansing terms, it's paper or water, and, as with driving habits, cultures rarely switch.

"Paper cultures are in fact using the least efficient cleansing medium to clean the dirtiest part of their body. This point was memorably demonstrated by the valiant efforts of a Dr. J. A. Cameron, who in 1964 surveyed the underpants of 949 men of Oxfordshire, England, and found fecal contamination in nearly all of them that ranged from 'wasp-colored' stains to 'frank massive feces.' Dr. Cameron, though a medical man, could not contain his dismay that 'a high proportion of the population are prepared to cry aloud about the footling matters of uncleanliness such as a tomato stain on a restaurant tablecloth, whilst they luxuriate on a plush seat in their fecally stained pants.'”