Carbon cake is starting to become a serious issue for me now. I've read that you should always maintain an 1/8 inch carbon cake. Do you guys agree? I'm currently battling a thick carbon cake in my very first, trusty $20 POS briar. When I first bought it, I could stick my index finder down to the bottom of the bowl. Now I'm using my pinky. I've been filing it down with a curved blade but its incredibly stubborn. Do I really need to get a pipe reamer or is there some other shortcut to grinding it down?