I lump all of those in with stuff like pressure points. They work, when they work. They are only dependable when you can get to them (to DB's point about a good striker), and some folks are taught to depend upon them MUCH too much.Ah yes, the "fight-enders". Eye-gouging, the always easily accessible groin in any scenario, the perfect throat shot. I forgot about those.
In fact, when I show using a groin shot, I usually am using it to get them to move a leg to block me. Most men are pretty good at doing that, and do it without thought. Similar concept with eye pokes.