None of my pipes has ever been reamed, and some are entering their fifth decade. (Obviously these were presented to me as nativity gifts.) I use the "chipping" method with a pipe tool as described above and occasionally smooth things out with a bit of sandpaper. After each smoke, I use a doubled pipe cleaner to brush out unburnt vegetatiion and debris. My cake is very thin -- less than a dime -- but serves to protect the briar, and the appearance of the pipes in the rack is neat and attractive. They don't look unmaintained, as if I'm content to let nature take its course. My strategy, FWIW, is to do the minimum needed to encourage a nice patina, without going for a tacky "better than new" appearance. But pipe maintenance strategy varies from piper to piper, which is fine by me.