I know from being younger this method works very well.
This is the exact same thing I realized I needed to do, the first time I tried to hang myself. And how incredibly painful it was. I remember back when we were kids, my friends would do this to each other. They'd choke hold. Just for fun, and I know from experience, it is painless. You'll literally just pass out from the blood being cut off, and very fast. The only difference now, would be nothing is letting go of your neck to regain the oxygen to your brain from the blood being cut off from your main arteries.
I thought of using a inflated inner tube that would act like an arm, but I worry it might deflate enough and just give me brain damage, if I woke up. I'll probably use the ratchet thing, that seems like a sound idea.
Outside of normal convulsions, no. Now hanging yourself, you'll fight most likely whether you want to or not, because it fucking hurts and unlike this method, you can feel it in your head so bad too, all the pressure.