I do all the kinds of regular maintenance that MSO described, wiping out the bowl, cleaning out the airway from chamber to slot, and cleaning out the mortise. So my pipes don't get crapped up with crumbly cake, or gummy build up in the airway. Still, periodically I do a deeper cleaning. This time around, rather than use alcohol I tried the hot water rinse, followed immediately by drying the pipe inside and out. The acrid smell of tobacco oils was nowhere to be found. Wiping out the bowl removed more of the residue than wiping it out dry, and the remaining result is hard carbon coating the chamber walls, not flaky cake. So far, no negatives.