I'd say the night-night method. You can use makeshift items instead of cornhole bags, the ratchet or gorilla tape however would be pretty important. I doubt that those are hard to come by. In my case they are available in a store that's within walking distance from me, and I live in a third world country.
Brain damage is the only risk for this method, but it should supposedly act fast, as in you should be dead in 5 mins. You either compress the right spots, you pass out and die, or you cannot find the carotid arteries, and hence you remain conscious and abort the attempt. But it's quite difficult to pull off. You can look up my contributions to the mega-thread, yet I have kind of given up on it. I am now considering the exit bag.