Even ear claps with cupped hands are pretty nasty. Wouldnt expect an average person to do them well, but if you did them really well, on both ears you might kill the person.
My personal ones would be doslocate elbow, throat, groin, eyes, or if desperate, Rick Grimes artery bite.
I didn't know that.
But yeah, the joints are the thing. I saw a video of a defense instructor taking on a methed up street thug. The instructor hit the thug fairly lightly on the hinge of the jaw bone, back by the ear. The thug wobbled, and then collapsed.
Game over, and pretty dang impressive.