My body is made of wood and stone
Today I learned that if you inform a small child of the existence of the Babylonian demon which lurks in bathrooms to get you if you don't wash your hands, you may also need to teach a small child about incantation bowls which can be made trivially at home in order to protect against such demons, but I feel everyone should know about incantation bowls regardless of a pressing need for them, so it all worked out in the end.

no subject
They had a demon described in exorcistic texts and warded off with amulets and incantations whose name was interpreted to mean "dirty hands," so, yes! Susceptibility to this demon is associated with poor personal hygiene around what we would call fecal-oral routes of transmission. Curing afflictions attributed to him can require clean water. It's not germ theory, but it's not, like, wrong. I know less about the sanitation of the time, but my understanding is that it was highly variable but not nonexistent.
(I learned about Ĺ ulak the lurker in bathrooms in the middle of a language class in grad school and have never regretted it.)