well to answer your first question your best bet is to, like everyone else said, put bigger bud on the bottom and the smaller shake on to

second off, the hole on the side is called a "choke" or a "carb" and it clears the pipe of all the built up smoke, whenever you let go of the choke you may want to suck in a little harder, and after you clear it, tap it irregularly to keep the bud burning