Hello Joe,
Your "Just watch me" technique would work for some students but not all while others need to feel what needs to happen such as your technique with the ski poles. Work with him on letting the turn come around farther or finishing the one turn before starting the next turn. When the turn stops short, the speed will build and then it can be too scary to try a wedge to slow down.
Also ensure his weight is moving to the outside ski in the turn and the inside ski leg can relax or bend enough to remove most of the weight from it similar to pedaling a bicycle.
YouTube has many videos for beginning instruction and that would help both of you. If you get him enjoying the beginning hill this way, have him buy you a beer.
Randy