i'm in the same boat pretty much, the only time I managed to pass out I just felt air being expelled through my nose. next thing I know I'm just slouched backwards, thinking about something completely irrelevant, then like waking from a dream, I was like 'wtf am I doing' and I immediately stood up and loosened the noose, and my breathing was pretty intense. I don't remember exactly where on my neck I put it, but the next few days I had pain when swallowing, which makes me think I need to put it on my adam's apple, which sucks. guess the pain doesn't matter if I don't wake up, but I haven't been able to recreate it.
you definitely have carotids, just need more force, I guess. I worry that the only way to close them for me is full suspension, but I don't wanna be hanging there in pain for who knows how long if I can't get them compressed correctly. some people die so easily, accidentally, while jerking off. used to sound pretty bad but now, wish I could go out like that, man.