After every smoke (pipes rotate every month or two) I scoop out the ash, wipe out the bowl with a paper towel or napkin, run a pipe cleaner through the airway, and polish up the entire pipe with special attention to the stem and bit. I store them stem-up in a stand or cabinet, with the air free to circulate and no pipe cleaners or anything else in the airway or bowl. This routine keeps the carbon layer sufficient but thin, and I don't need to own a reamer, and the chamber stays the same size. When needed, I remove the stem and do a more through cleaning. For storing, I leave them where they are. If I were packing for a move or longer term storage, I would let them dry out well, and then pad them extra and pack them carefully in cartons or plastic bins. I'd be careful, because pipes are something notoriously lost in moves.