I grew up working at the local riding stable for years. The guides got stuck with the worst of the unsafe horses. We had one gelding that ran away with everyone. By accident we found if you stopped pulling back, the game was over and he'd slow down all by himself. He was the one we used to always try a one rein stop with. I have to laugh at that! We were doing the "one rein stop" before John Lyons ever coined the phrase and started charging to teach it to people!
The horse I have right now I've owned for 8 years. She has never been "opened up" on the trails or anywhere and doesn't have a clue that running off is even an option. I plan on keeping it that way