The boy I am riding right now was trained by a young rider who used his mouth to balance. As a result, I have to deal with his head-tossing and general reluctance to be on the bit. He will do it, and he is getting better, but he's just not used to having to accept something in his mouth even if it is soft and gentle (it's a pee-wee). It occurred to me the other day I could always ride in a hackamore... Are they legal? Is it possible to get a nice headset in dressage with one? If so, what are some better brands/varieties? I wouldn't want to completely brush over his bit problem, but I don't want to constantly fight, either, and if there's an option he'd be happier and more willing with I'm all for it! Another concern is that he's an Arab, so quite headstrong, would I have sufficient control?