So I bought my first two briar pipes - a Morgan Bones and a Rossi. Both of them came with a black coating inside the pipe. Is this common? I’ve heard a number of smokers talk and debate about creating a carbon cake in a new pipe, and they spoke as if there was no coating at all inside the bowl. Are most pipes sold with this coating or do the two I bought just happen to be in the small percentage of those that come coated? Just curious.