I've heard it's good practice to romove the unsmoked bits of tobacco from the inside of the bowl. Trouble is that it's always stuck on there pretty well and there is a lot of it. I go in with a pipe cleaner and it gets out a lot of it but there are alway quite a few stubborn pieces that the cleaner won't get. I have to remove these pieces manually. It's a new pipe. About 6 bowls in. Is this just something that I have to put up with until a proper cake builds up or am I doing something wrong?