My dad smoked a pipe from the late sixties to the early eighties, Borkum Riff Bourbon Whisky in Dr. Grabows. He told me that the way he broke in a new Grabow was to fill half-way, light it and enjoy a few puffs, and then he'd hold it out the car window while going down the road. The air rushing into the bowl would burn the tobacco down and get the cake built up.