OK, I'll bite...what is the hard black stuff almost like baked on carbon "something" that accumulates on the inside of my firepot? It's a groan to scrape off when I'm doing my weekly cleaning....Is it pitch from the pellets baking on or is this a normal thing that happens with all pellet stoves. I used to think they were "clinkers" 'cause they kind of look like a coal clinker but have seen here that pellet clinkers are different animals altogether then what I'm seeing here...