I used to have my hand regularly crushed by a boor in my office of London Underground. After the first few times, I quietly mentioned that I didn't find it necessary to try to break my hand if he wanted to shake it ( he used to get his thumb on the side of your index finger knuckle and his index finger on your pinky knuckle and grind...) . His response was literally "Piffle!" and he walked off. I got my revenge at the next meeting, when he grabbed my hand I screamed. Lawks, was he embarrased. I mean, how good does it look when you're over 6 foot, built like a brick out house and you go around hurting small women for no apparent reason in a work situation? Strangely, he wouldn't come near me at all after that and I used to wind him up by edging closer to him, just to see what he would do.

I like the african nod thing, although you may have some confusion around penitent catholics ( meia culpa.....).

TTFN M'Lady P.