I know this is easily my dumbest post, but do you think they had anything even resembling toilet paper to use in the World of Avatar before it became a thing in Korra's time? I woke up from a dream when I was 25 and asked myself: What must that world smell like and how do people keep their cheeks clean? I mean, I can imagine waterbenders effectively learning how to bend a bidet-like stream and airbenders...well... okay, let's not get into that. Pun fully intended.
But what is the hygiene situation like in that world?
