It's part of the lore of being a chimney sweep.

Having a Mary Poppins-themed birthday party when I was 5 - all my friends went in dresses, and I went as a chimney sweep. I was a real tomboy.

acted like a chimney.

He (Zane) had said now that we have a chimney, Santa can come in the real way.

Oh yeah, I smoke like a chimney,

Dreams are real; dreams exert influence