4. Urine Tooth Whitener
One of the more nauseating beauty practices of the past was collecting fermented animal and even human urine for use in tooth whitening. Urine, when left to ferment for several weeks, produces ammonia. Ammonia is sufficient for many purposes, of which tooth whitening is a more horrifying example. The ancient Romans, in particular, were widely noted for using urine-based tooth whiteners.
Roman author Catullus noted that Romans used both animal and human urine in a mouthwash intended to whiten the teeth. He wrote in praise of urine mouthwash,
“Where man who’s urined therewith loves a-morn
His teeth and ruddy gums to scour and score;
So the more polisht are your teeth, the more
Argue they sipping stale in ampler store.”
It appears the Romans were quite fond of the use of urine-based tooth whitening. They used both urine and feces extensively and let no product go to waste from their system of public toilets.
Urine has long been a valuable product for laundry, gunpowder, and more. Urine from chamber pots was often saved by farm wives to create ammonia for laundry. In the 18th century England, night soil men established a lucrative business of collecting urine for processing into saltpeter for the creation of gunpowder. While we may call them waste products, they are undoubtedly useful, if disgusting.