This is a great rebounding basketball drill to work on the fundamentals of boxing out, but then also work on the players ability to release and go get the rebound after the box out. Boxing out and driving the opponent back is just the first step, and is only half of the battle. The great rebounders are able to do this, and then finish the play by releasing to gather the basketball at its highest point. This drill isn't going to use a ball, but it is still going to practice that quick and explosive jump to get up off the ground on the rebound.
If you want to be a great shooter you do shooting drills, the same goes for rebounding. You have to spend the time working on the fundamentals and technique to be a great rebounder. This drill can be added to the end of your practice or to basketball training. If you want to be good at rebounding, you have to spend the time working on it.