There's already a mega threadt about sn:
https://sanctioned-suicide.net/threads/sn-megathread.1156/
Azure decribed the effects of an verry good, maybe that will answer you question
Still each human being reacts different so theres no 100% chance of knowing what will happen, only thing u can do is increasing your medical knowledge and knowledge about your own health status, resistances, etc. , maybe get some information from doctors you can abuse to support your death wish...I like the imagination of Diethylether causing unconsciousness and opiates releasing me from unwanted pain, that'd be something u could just combine with a deadly allergy, toxic cocktails, hell u could even use it to get hit by a train or any other method that needs courage without doubting it, but I wouldn't recommend involving other people in your own death and causing a trauma or worse...
SN seems to be one of the smoother methods and it's not poisoning his own body, still it could cause awful headache and stuff due to its effect on your oxygen level (if I remember right)...I'd prefer my organs to stop working on a different way
If you're bored go check out the YT channel 'chubbyemu' he lately switched to medical videos, it's crazy how easy you can die from eating some days old pasta or how the bones in your body just break apart from eating too many vitamin gummybears