Rule of thumb - dying is usually going to hurt. Or at the very least, it'll be uncomfortable.
SN will make you feel like your stomach is melting. But it'll work.
N is impossibly unreliable to obtain. But it'll work.
Opies and Benzos w/alcohol require MEGA-HEROIC doses. But if you've got doses that big, it'll work.
Firearm inside mouth, aimed toward the deep center of the brain. It's gruesome. You will be discovered by people who will invariably suffer PTSD from what you've done.
But it'll work.
Partial suspension is unreliable.
Night-Night is even more unreliable.
SO... Why not a little of each? That would be my method if it ever had to come to it.
Boatload of benzos, few sips of alcohol. Tape the night night to my neck. Get in the noose. Suspend til The End.