just my opinion but i feed live, its more natural and that's what snakes do ,they kill stuff and eat it , the whole gas chamber thing is way overboard in my opinion unless maybe your killing a bunch of them at once , personally i go and get a mouse , i don't pre kill it, but i stun it by flicking it in the head, that way it stuns the animal and disorients them , then drop it in the feeding tank or whatever you feed your snake in, usually my snakes snatch them up before they get there bearings completely back , i know a lot of people would say that is cruel to do that but i don't think its any worse than making a ghetto gas chamber and killing it that way . I may be wrong, but back in the day, like before people could order dead rats online , i never herd of frozen rats , people either feed live , stunned or pre killed. all this is just my opinion , im not saying that it is the wrong or right way , i say do what your comfortable with and what your snake is comfortable with