Oh,yeah. That dribbling from the spit valves (yes, that's what they are called).

Put the horn over a waste basket or toilet or something, press the valve lever, and blow the spit out. Do this whenever you wish, but some folks get upset about using the floor or carpet so I suggest the ground, a toilet, a waste basket, or your lap (don't use the lap of the guy next to you unless you're a lot bigger than he is).

If your horn starts to sound like you're playing underwater, bubbling and all, you'd best empty your spit valves.

By the way -- there should be cork or other seals on those valves. If there aren't you should get some put on or you'll dribble all over the place.