We don’t know what these folks were smoking, and, frankly, we don’t want to know. But they have produced a pretty dramatic test case for ultrasonic cleaning. They put their tar- and gunk-encrusted glass pipes in an ultrasonic cleaner for a three-minute cycle and they get dramatically cleaner. Another cycle, and they’re barely dirty. Then a final cycle and they’re just about brand spanking new. But, really, if it takes nine minutes to get this gunk out of a glass pipe, do you really want it coating the inside of your lungs? Hard to put those babies in an ultrasonic cleaner!