Actually that is a bona-fide release drill. You may want to cover the couch with an old blanket, and possibly put a couple of pillows down as well to help contain the ball.
The last thing you want to have to explain to any woman, is how lane oil stains got on her couch.... no matter who bought it...
You should look around locally for a certified coach/ instructor to help your son move to the next level. Of course you can have him come to this site to get questions answered as well.