I had an idiot gelding that I didn't feel safe on when he came unglued. So I got off. Carried a lungeline on my saddle and whenever bending and circles didn't work, I would get off and lunge his little butt and do lope/long trot transitions until he decided to pay attention. He would only fight himself and I stayed safe. When he started slowing the trot down or turning his ears to me, waiting for a cue, then I would praise him, get back on, and head back down the road. If he acted up, off I would go and make him work up a sweat. It was always much harder on him if I got off. It worked pretty well, but you have to be patient and praise the good behavior and make bad behavior more work.