Gah, I can't stand the one rein stop. I honestly beleive that fi I pulled my horses head around to me knee any faster than maybe a trot, he would either trip or flip over. I think it's more dangerous than the horse bolting in the first place.
you are right, it's dangerous if you do it at the trot or faster. that's why you don't do it right then. you spiral the horse down. the main point is not the head bending, but the hips disengaging to stop the front feet.
you go forward at the walk, sit down with your seat (deflate and melt into the saddle, turn your body into the letter "C" but without leaning back), say whoa, and pick up one rein to bend him around and disengage him
when you can stop your horse with just your seat, then go to the trot.
trot, sit with your seat, pick up one rein SLOW not yanking....and bend him around to circle down to be able to safely disengage the hip. he stops, you release.
same with the lope.
I use the one rein stop for bolting horses and it's worked 100% of the time.
You can then get the horse to stop with just your seat and that you barely pick up on one rein.
I agree with the idea of just making him go and go and go. Sit relaxed, stay calm, and just lope and lope and lope. Ask for a slow down, if he doesn't respond, lope some more. Once he responds to your cue, then he can quit.
This is a good idea too. I have done this in an arena where I know the ground is good and not full of gopher holes. It does work. You keep your body relaxed and just go with the horse. If you tense, you'll just prolong the runaway.
Then, when the horse is trying to slow down, speed up a bit, then you choose when you slow down and stop.
It works....but it can take longer than the use of the one rein stop.