Maybe a combo of methods? Choking down N, then quicky securing a plastic bag with a face mask over nose and mouth so the plastic doesn't block passageways, and an ice pack inside to counter the heat build-up? If we pass out, then the carbon dioxide build-up--hopefuly wouldn't trigger survival instinct to kick in--or would it? Damn. I always wanted to go via helium ot Nitrous, but could never figure out regulators, flows, valves, all that. I just a ready-to-use handy dandy stupid-proof gizmo. That's what I want Santa. That and a very peaceful pill (a bottle of them). Amen.