People only pass out from head impacts if the brain damage is bad enough to be permanent, but don't always pass out from receiving permanent brain damage, so this is really bad, too. I've read (but probably on Reddit rather than a real source) that people pass out from hypoxia well before any permanent damage, so choking people is safer, especially if you learn to do a blood-choke properly so don't risk crushing their windpipe. Alternatively, lure them into an operating theatre where a qualified anaesthetist who knows their weight and medical history is waiting, as they're really the only people who should be making other people pass out.

Honestly that's probably safer