The ancient Romans were nothing if not resourceful, even when it came to dental hygiene.

Believe it or not, they often used stale urine as mouthwash! The key ingredient in urine is ammonia, a potent cleaning agent that helped whiten teeth and combat bad breath. This unusual practice was so common that stale urine became a highly sought-after commodity.

The demand grew so much that Emperor Vespasian, ever the opportunist, imposed a urine tax on those who traded in it. Public latrines turned into collection points, and merchants profited from selling the liquid gold to those in need of a sparkling smile.

Despite its questionable origins, this Roman innovation showcased their practical approach to cleanliness—though modern toothpaste users may feel relieved times have changed!