i'm planning to place a heavy enough bucket on a chair leaning against the wall, then i'll move my couch near there and lie down with my head inside the bucket.
Plain SWB looks beautiful on the pictures, but it's rather hard for many people to accomplish in practice. Long hyperventilation may cause headaches (hence excluding the "painless" aspect) and still be insufficient to limit CO2 to the extent when the sense air hunger doesn't occur before fainting.
I suspect that violent hyperventilation may be non-optimal, because it induces too much stress that can result in producing CO2 at a significantly higher rate than you have at rest, and this could partially negate your efforts to reduce CO2 levels in the bloodstream. Besides that, it seems that it is important to train your tolerance to high CO2 levels by repeating long breath holds over and over (with trying to bear arising urge to breathe for maximum possible duration each time) in order to succeed at fainting eventually.
Agreed, this method is way easier and faster than relying on hyperventilation.
You shouldn't feel any pain when drowning if you induce persistent unconsciousness beforehand, that is the key feature of the plain SWB method and its enhanced version that involves gas asphyxiation.
