Of course they work. The method has been used twice now, and both those inmates are dead.
So far, Alabama is the only state to execute anyone with nitrogen gas. It didn’t go off very well either time.
The first the inmate “appeared conscious for several minutes into the execution, and shook and writhed for about two minutes after that,” followed by “several minutes of deep breathing before his breath began slowing,” according to media witnesses (see story here).
The second inmate “shook and trembled on the gurney for about two minutes with his body at times pulling against the restraints … followed by about six minutes of gasping breathing,” and wasn’t pronounced dead until 32 minutes after the execution began (read story here).
I’m not saying these convicted killers didn’t deserve the death penalty, although it’s a bit surprising they didn’t die of old age before being put to death. The first guy was on death row for 36 years, the second guy for 25 years. Capital punishment isn’t an efficient process. It isn’t cheaper than life imprisonment, either.
But if a civilized nation is going to execute people, it should do so humanely, not use a method akin to smothering someone with a pillow. However, if they’re going to suffocate people, they might as well have a guard enter the inmate’s cell and give him the pillow treatment. It would save everybody a lot of unnecessary hoopla.