They are always looking for a humane way to execute the dregs of society that sit on death row they complain that poison oozing through someone's veins is not humane. They know that freezing is one of the least painful ways to go. Would a chamber that was flooded with liquid nitrogen be a more humane way to do executions? (I know that a ton of liberals are going to ring in that the death penalty is wrong, it is just a hypothetical question)
Put them into a coma then whatever's cheapest way really . When they are in a coma they are practically dead and won't feel anything after that
Similar to the last days of life... I've seen this under another name...