Compression is a simple method of self-deliverance that relies on no complicated equipment and does not require drugs. The main veins and arteries of the neck are compressed in such a manner that the pressure remains after the person has fainted. Fainting, and death, is a result of lack of oxygenated blood to the brain. It is very quick - fainting occurring within a minute and death following within a few minutes. (In rare cases, death may be accelerated by cardiac arrest after loss of consciousness.) One of the main methods of achieving compression is to use a tourniquet around the neck, carefully positioned so it does not obstruct breathing. Another method is to use continuous looping, and a third is the introduction of mechanical devices [aka a "hookless" ratchet tie-down... those are available ~everywhere... usually used secure a load in the back of a pickup truck, e.g.]. Some momentary discomfort is possible, but brief, and can be minimized with careful forethought.