I use Magic Eraser on stems after about 6 bowls to keep them nice and clean. After everything I go through to get them all fixed up and clean, I want to keep them that way. No buffer here, just good old elbow grease. I use Paragon Wax on my smooth bowls, and after every smoke I wipe the bowl down with the Dunhill Cloth, works well. When I put some Paragon Wax on the bowl I will also wipe down the stem, works well so far. If out in the sun a lot I would also use Lip Balm unscented, every little bit helps. I like my pipes clean with minimal cake, maybe a dimes worth I would leave on. That is of course from my own smoking of the pipe not someone else's, that is from an estate pipe, yuk!! I have come across some pretty dirty ones and am amazed that someone would smoke it like that. Totally gross.!!