Do any of you put subs up by means of smothering? How long are they or deprived of oxygen?

Oh, obviously there are two different ways to put a person out, or two main categories. One is a blood type choke and the other is smothering or deprivation of oxygen by means of smothering, bagging, drowning or other similar means!

Knocking out? Choking out? This is totally not what I thought this thread would be about.

I understand this is RACK play, but perhaps I am too old school for this. I "toy" with a subject with breath play, including the pressure on the arteries/veins. I would never do this to a blackout. Over the decades, I have had people faint in session, and that is stressful enough. I've long existed in the grey area of the law and kept myself out of trouble. I'll go ahead and continue that trend.