There aren't too many alternatives that are this effective in that regard. Even isolation isn't as effective.
Oh, so true! I grew up in an era where the wooden paddle in the vice principal's ofice was a real threat. But as I recall, we had maybe two or three actual paddlings per year -- a pretty low percentage. Part of the threat of being paddled was the humiliation when you came back to class, since the other kids would cheerfully remind you of the paddling every chance they got for several weeks. (That was the "upside" of peer pressure!)