When doing this drill, it is very important hat the players focus on quick, accurate passing. Make sure that the passes "pop". (Note: the ball rotates with the clock)
Also, emphasize the importance of not only getting your chest and shoulders out of the water for passing the ball, but receiving it also.
Variations can be made by challenging the players to complete all the passes around the horn in a certain period of time, 5 seconds, 10 seconds, etc...