I can't speak for SN, but for Nitrogen I just learned how deadly it was. I definitely didn't feel it was a peaceful experience from my two test runs. Granted I didn't follow proper protocol in both because I wasn't prepared to CTB yet and didn't have everything set up yet, so I didn't pass out from it. For context, I scrunched the air out of the exit bag and pulled it down. Then, I filled it with Nitrogen gas.
During the first test run, I had 17 LPM of Nitrogen running as indicated by the Argon regulator (I don't know what's the Nitrogen equivalent but it was the recommended level by previous users). I wasn't expecting anything, as in my mind eye's I thought it would work like anesthesia, but the experience was different. In under less than a minute (could be 15–30 seconds), I was hit with a wave of symptoms that I think followed this order: ears ringing, feeling I needed spit/puke, disoriented, dizzy, and feeling faint. When the symptoms came, I knew how deadly the method was and how harmful it would be to the brain. I even kicked one of my cylinders by accident without even realizing it until I took the exit bag off. Because I was doing a test run and didn't have the proper protocol set up, I took the exit bag off and turned off the regulator. I was so disoriented that I even forgot to turn the cylinder valve off after I turned the regulator off, so I began unscrewing the regulator from the cylinder without remembering to turn off the cylinder valve first. Fortunately, as I was unscrewing the regulator, there was some loud gas leaking out of the cylinder valve, which reminded me in time that I had to turn off the cylinder valve first otherwise the Nitrogen would've exploded out of the cylinder valve. The nausea and ears ringing seemed to clear up pretty fast, but I was disoriented for about an hour at least. The experience felt like taking a huge amount of Cannabis edibles, particulary when you had too much. I think my eyes also felt itchy a bit.
During the second test run, I had 13 LPM of Nitrogen running as indicated by the Argon regulator (again I don't know the Nitrogen equivalence). I wanted to see if I could achieve this 'happy' hypoxic state with a lower amount running and if it was 'safer,' so I set it to that amount. I had different sensations this time. This time I felt that my heart rate spiked, a sense of breathelessness, and lightheaded. These sensations were intolerable and I took the exit bag off and I turned off the regulator and the cylinder valve. It definitely wasn't the CO2 buildup that was causing the sense of breathlessness and fast heart rate, it was the Nitrogen.
All in all, I wouldn't say these experiences were peaceful experiences, but I imagine that if you do the protocol properly and had a large amount of Nitrogen pouring in, lost of consciousness would come quickly, so that you could bypass these intolerable sensations. You need to be in an extremely hypoxic state for this to happen. The method is like a gunshot in gaseous form and you would need to ensure that you can sustain it after you lose consciousness.
Hypoxia is hypoxia, there's no way around that. You won't get an 'anesthesia' death with this method. I think my experience tracks with what I read for some on SaSu, things I've read online, and the videos I've watched. I think this 'happy' hypoxic state that is being described is when the gas amount is low, but it might be ineffective for CTB. Originally, I thought Nitrogen was the new N, but it wasn't the case, at least if you're going to use it to CTB.
