Did Romans Really Use Urine as Mouthwash??? #facts

Yes, but not everyone brushed their teeth. A more widespread use of urine was as a sort of laundry detergent.

This isn’t as crazy as it seems. Urine consists mostly of water, but it also contains ammonia, or NH3. If exposed to air for too long, the water in urine evaporates, leaving just the ammonia. Ammonia is actually oftentimes used in toilet bowl cleaner, as it has powerful antibiotic qualities - it is toxic to most life (which is why your body needs to get rid of it), and will kill many unwanted living organisms (like bacteria) on your clothes. Brushing their teeth with urinal ammonia probably isn’t a good idea, not only because ammonia is toxic if consumed, but also because if the person producing the urine is sick, the urine may contain pathogens - which, in ancient times, could mean cholera, dysentery, typhoid, and other nasty diseases.