No, I'm anal about my pipes at all. I just use them until resin starts leaking out the shotgun hole. Nah, just with this one pipe I did that once. It was so full of resin, everytime I get the bowl heated up smoking, resin would leak out the shotgun hole and all over your fingers. It sucked actually.

I just clean my pieces when they start smoking a little harsh, or if all I can taste is the resin and not the weed, or, if the pipe becomes clogged, then it's time for a cleaning.

Not after every bowl though.