Oh sorry... Just woke up, so I read "was it SI?" as "What is SI?"...
As for my preferred method, I had bought formic acid so that I could mix it with sulfuric acid to produce carbon monoxide. CO is by far the most peaceful way to go. But it turns out, you have to "rince", or "wash" the resulting gas with some other chemical so it is breathable... Because of course you do! Couldn't just be as simple as mixing the two acids, like I'd read, like, EVERYWHERE before that...
So yeah, since I have stopped all contacts with the outside world, including cleaning the apartment and taking care of bills, now I absolutely *have to* go back to the tourniquet, and make it work no matter what. And soon too!
What made me stop at that time, wasn't that it was very unpleasant, which it was... The real reason is I didn't feel like it was doing anything towards the intended goal... I felt all the rest, like the exploding head feeling, the difficulty breathing, etc... But zero progress towards even passing out...
But still, I don't have any other method available, soooo...