Siphon effect and partial suspension?

[Stickyfinger]

watch this video, I'm currently trying to do it but I don't pass out as easily as she does. I even hang myself multiple times and stop as soon as I feel dizzy and the only thing I get is a headache, is there a trick or something?

 

[PrettyMoose]

Either she got incredibly lucky with the placement of that collar as well as the anatomy of her neck, or that collar has padding to specifically press on the carotid arteries.

 

[Brokenwings]

So are the saying you have to get dizzy stop and do it again to pass out. If I chose to ctb I'd like to pass out as quick as I can. I want the closest I can get to dieing in my sleep.