Gas chamber? When I was in college I worked one summer in the Boston Animal Rescue League. In the Lethal Room they electrocuted stray cats and dogs, one of the most horrible things I have ever seen. You have no idea. I told them I would quit if I had to work there another day and went home in tears. Gas is a kindness by comparison.
Read one personal account from a ‘net search on gas chamber for euthanasia and I think you’ll change your tune.
I would be a *wreck* to witness any of this.