Hey just to be clear, even though it would be very inexpensive and simple to try, you can't kill yourself by holding your breath til it's gone.. You'll pass out and then you won't be able to hold your breath anymore because your body will just breathe regularly when you're unconscious.
Also, if you want to shoot yourself through the mouth for whatever reason, make sure you aim at the brain. Sometimes people will shoot through the roof of their mouth, and the bullet will just come out your nose area and **** up your face.
Can you explain why? Im generally curious why someone would want to kill themselves, I just recently had a friend commit suicide and having a hard time understanding why.