No, that's what I'd call an acccident waiting to happen. Like the owners of a cute lickle foal who taught it to jump up on their shoulders with its' front hooves: it was still doing this at 3 years old and 16hh.
Imagine if someone taught this and (worst case scenario) the horse tried doing this while adjusting something at a competition and it had studs in?? OUCHH
I've taught my mare to smile on command but thats as far as I'm going!
When I was young I taught my pony to shake hooves, my parents loved me! Every time you went in his stable he waved a hoof at you.
Another day but about the same time (I was a slow learner) I played with our colt foal, so he would rear up at me, I wasn't that old and was probably being a horse too, as I was for years. it took my parents a long time to reeducate him too.