Did you see the examples I mentioned? I said I've seen it work for biting, kicking, and teasing. No where did I mention beating. However I think that for death row criminals the eye for an eye method can't really be used. Capital punishment can punish an innocent party (ie close family and friends).
I'm not going to argue with child beaters. It's when the child beaters start bemoaning other forms of punishment with their hypocrisy held high.
Beating children can also punish an innocent party. Of course, that didn't occur to you, did it.