Nitrogen is cheaper. It is (or was once) used to euthanize stray dogs. It’s quite safe as there are no toxins used. Respiratory distress is caused by the inability to remove CO2 from the blood stream. Barometric chambers used to train flight personnel cause hypoxia, and I know from personal experience it is quite painless. (The Bends-like after effects can be annoying, but Nitrogen hypoxia will not cause that, and the convict will not be around to experience it anyway.) Hypoxia is not only painless, it produces a pleasant feeling of intoxication. Of course, knowing that you are gulping your last breaths may be a real buzz-kill.
Yes, I knew these things already. Nitrogen is indeed cheaper, but it doesn’t produce a comical timbre in one’s voice.
You sound like someone who’s been a diver, I think this way would be humane. I’m just trying hard to care about the pain of a murderer.
Isn’t nitrogen now used to kill hogs?