Unconscious, and not breathing?? That would be scary.
For the stuff we were doing, it was very deep, steady, and moderately faster than usual breathing, nonstop - the instructor thought afterwards that I may have been doing it "too fast", including the breathing out part, rather than letting it flow out naturally, but he'd never encountered someone having a seizure before. Regardless, I'm not going to personally experiment with it anymore, but I suspect I'm a fairly extreme outlier.
For the stuff we were doing, it was very deep, steady, and moderately faster than usual breathing, nonstop - the instructor thought afterwards that I may have been doing it "too fast", including the breathing out part, rather than letting it flow out naturally, but he'd never encountered someone having a seizure before. Regardless, I'm not going to personally experiment with it anymore, but I suspect I'm a fairly extreme outlier.