My fathers spankings never hurt me as much as the thought that he would spank me in the first place.. The disappointment in me probably did more to straighten me out than the actually spanking... but then I loved my father and I knew he loved all of his children. You can't say that about every parent.
Oh the old 'hurts me more than it hurts you' routine.
If you have to use violence against a child, then you are a failure.