Towards the last quarter of the bowl I will stir the ash and dump it out. Then I lightly cover the bowl with my index and middle fingers and blow a short blast of air into the pipe. The two fingers direct the ash that comes flying out away from you. This way you don't get a mouth full of ash the next time you puff. Then I stir, lightly tamp, and relight. It's especially effective with Virginia blends and greatly improved the flavor of the last part of the bowl.