There was a person here, @Trashcan. I remember for sure he tried this method and failed only because he always woke up finding himself lying on floor with bag off his head (seems like he continuously teared it off while being unconscious). As far as I remember, there is no exact solution to prevent this. Somebody suggested to use cuffs, but this would add more stress and panic. Please, correct me if I am wrong. I am gonna use inert gas method in future, so this problem is important for me as well. I did not come to exact conclusion, but I am thinking of using the long rope or something like that just to make my hands bandaged (no knots or smth, just wrap it around as much as possible and make it tight). In case something goes wrong, I can just easily get rid of the rope.