Yes, it‘s a very effective way of reaching (or pushing) someones limits. It‘s like breath play (which i only touched lightly so far) and you have to trust your special other completely (i do!). At the last session, she showed me her fightergirl skills by holding my neck in a very tight grip i was in no position to defend. Very quickly, i wasn‘t able to breath and felt quite dizzy. She told me afterwards that if she would have kept the pressure a few seconds longer, i would have passed out. And there would be quite some guest requesting this kind of experience. I was very impressed by her technique, force and skills.