Pipe cleaner every time and only recently started wiping bowl out with a paper towel to slow cake growth. Ream as needed. If a pipe has clogged a bit I'll use very hot water dribbled into the bowl, let it sit a spell and then work on it with a shank brush and dig around the draft hole with a paper clip til it's cleared. Only when that doesn't do the trick-seldom-will resort to iso alcohol, which will make an even bigger mess in the sink than water.One never needs to clean with alcohol, though lots of folks seem to think it's a good cleaner.
You can avoid alcohol altogether, save time, money and booze by running a stream of very hot tap water into the chamber and out the stem. You can do this the instant you stop smoking, or days later when it's cold.