Gummy Gunky System Pete's?

The system pipes are in a class called "well" pipes. Most full bent pipes have a well. It is there to collect moisture and keep it from getting to your mouth. It works pretty well if you aren't the type of smoker who tips their pipe to dump ash or something. Anyway, yeah the well collects a lot of crud. If you buy an old estate it will typically be pretty nasty. I am pretty fastidious with the few I have. That's because I think a nasty well contributes to a bad taste. So after every smoke I clean the airway and use an alcohol dipped q-tip to clean the well. I also clean the hollow end of the stem if it is made like that. It seems to work. But I still occasionally forget what pipe I'm smoking, dump some ash and get a mouthful of tobacco juice on the next draw. That's why I have a small number of well pipes.

There are even some half bent pipes that are made that way.