Granted death penalty opponents are biased, but it's often said that barbituate overdose is a very unpleasant way to die. I've also heard opiod overdose is unpleasant.
I was once helping take down a 10-foot weather balloon full of helium, and took in two breaths in a row of pure helium. I started to get tunnel vision, said "whoah", sat down when I realized I was about to lose consciousness, fell down, and twitched just long enough for my friend to realize I wasn't joking around before I woke up. From my experience, hypoxia from pure helium is slightly pleasant all the way to loss of consciousness. I presume pure nitrogen would be nearly the same.
Let my last words be something witty in a high-pitched helium voice.
(Side note: pure nitrogen hypoxia would not be a particularly humane form of execution because the condemned would likely fight it by holding on to their last breath.)
Yup, AFIAK hypoxia is the best way to go. Survivors who are rescued in time (or, like you, self-rescue) don't have a bad experience. The MAiD protocol used in Canada likewise appears to not be a bad experience as the only thing the patient experiences is anesthesia.
I'm also coming to the conclusion that inert gas hypoxia is going to be my way out. My end has to be, as far as I can make it, painless and polite, meaning a happy exit with minimal inconveniencing of as few as possible other people. Any suitable substance for this seems to be taken off the market, even basic stuff like metal nitrites (as used in curing meat. Try getting hold of a nontrivial amount of this in the UK). I don't have the inclination to follow up Project Peanut; I don't have the background for this.
I fully understand why this has been done, to stop people who only intermittently get the urge, but for someone like me it's a major bloody inconvenience, so inert gas it most likely is.
(The above is not an opener for a discussion, it's an FYI for a different perspective. Please don't respond).
I had general anaesthesia for a surgery, and I can remember the falling asleep was only very slightly uncomfortable. so I think it can be done - once I'm under, just cut out something important and throw everything in the furnace.
I was once helping take down a 10-foot weather balloon full of helium, and took in two breaths in a row of pure helium. I started to get tunnel vision, said "whoah", sat down when I realized I was about to lose consciousness, fell down, and twitched just long enough for my friend to realize I wasn't joking around before I woke up. From my experience, hypoxia from pure helium is slightly pleasant all the way to loss of consciousness. I presume pure nitrogen would be nearly the same.
Let my last words be something witty in a high-pitched helium voice.
(Side note: pure nitrogen hypoxia would not be a particularly humane form of execution because the condemned would likely fight it by holding on to their last breath.)