"As far as the Romans were concerned, the best and therefore the most expensive urine on the market came from the country of Portugal. It was supposedly the strongest urine in the world and thus, the choice for whitening teeth."
https://www.ancient-origins.net/history-ancient-traditions/money-does-not-stink-urine-tax-ancient-rome-003408
@estherschindler
That's a great quote.
I think I now know all I need to know about this today.