I don't often get a bowl that smokes down to nothing but "fine white ash". Usually, when it happens, it is with a well-dried tobacco smoked in a cob that has had plenty of time to rest. I imagine that's when a cob is at its most absorbent. Moisture is just a part of pipe smoking; nothing's perfect, I guess. If a bowl gets bitter or too waterlogged too maintain a light, I dump it. I'm a pipe smoker, not a masochist. I've used the "blow back through the stem" method, the "flick the moisture out of the stem" method, and the "swab your bore with a pipe cleaner" method. They all work, after a fashion, but when a bowl is done, it's done. Moist tobacco, a saturated pipe, smoking too fast, high ambient humidity...all these conspire to ruin your perfect bowl. Don't let them get the upper hand and interfere with your enjoyment. Hell, if you only enjoy the top 1/3 of a bowl, so be it. Smoke on.