Just doesn't seem like it's worth it, man. Like, I guess I don't understand why you'd want to go in such a messed up way. I get the end result is death either way, but it's far from "effective".
Why worry about the cost expense? Any money you haven't spent in this lifetime will be left behind anyways. Isn't it better to spend some extra cash to get in a comfortable position?
You're essentially asking if it's "effective" to put in the unnecessary time, effort and resources into making you die in the most messed up way possible. It's like, no, obviously not. It's not "effective" to have your body wiggling around across the floor/surface. You'd most likely bump into things because you're fighting against a human instinct and it's a human instinct's to fight against whatever is killing the brain. You're also not going to die "quietly" from this method, which can alert other people to contact some kind of service. You also need to take into account that BECAUSE you're moving around / wiggling around, that the bags can come off. But now you're tied up on the floor/surface - how are you meant to put it back on your head at that point? And if you have some "back up method" of escaping, then wouldn't you just escape during the process because it's torture? etc. I could go on ages about why this isn't a good idea, but you get the point.
Like, I guess what we define as "effective" is different. Seems like so much would go wrong, and the chances of them going wrong is a high %. There's a reason why not a lot of people use this method.
I understand you maybe have some kind of hyperfixation with this method, but it just seems like a masochistic way to go, to get the bare minimum result. I wouldn't do it personally.