I bought a ratchet strap without the hooks a couple weeks ago and tried to tighten it as much as possible. The thing with carotid compression is that it's hard to get the spot right and using the ratchet you're doing it slowly. Instead, how one forum member said, to pass out quickly, you would have to tighten it instantly and firmly so both your left and right arteries are compressed.
I've tried using my fingers, got the same feeling when you're out of air and had to stop, tried using different cables and still couldn't pass out even while feeling dizzy. With the ratchet - same result, just dizzy but can't pass out.
Still trying to get it right but because of the various bruises and likelihood of the red marks on the face, I'm a little afraid of doing it not living alone.
Edit: I see you're new
Welcome to the forum and I wish you the best to find what you're looking for in this wonderful community. The method you're referring to is called night-night. You can look more into it in the resources thread