I’ve lived a lot of places, many with fireplaces and chimneys. Never had one big enough for a large raccoon to get down, let alone a human. Are those really that common?
I was thinking the same thing. I don’t believe that chimneys built since the fifties at least have flues large enough for a person of any size, and even if they did, there’s the damper. My mom’s house was built in the sixties and none of the flues are large enough to even enter to get stuck.