the ancient romans used a chemical called ammonia (derived from urine) and fuller's earth (a clay that can absorb grease and oil.) to clean their woolen togas. "fullonicae" were very famous, with at least one in every town of any notability, and frequently the largest employer in a district. these laundries got their urine from farm animals, or from special pots situated at public bathrooms. the workforce made so much money that fuller's guilds (a group that works in solely one job, in this case, making fuller's earth, this special clay.) were an important political force. also, the government taxed the collection of urine and sent people to jail for wetting their pants.