You hand out an all-metal guillotine-frame and a blade that goes into it, then take it back and assemble the guillotine into its deadly form.
Chop a small carrot in the stock and let the pieces fall...then with some fanfare, you place your finger into the same place on the vicious-looking mini-guillotine -- the blade passes right through your finger, yet easily chops a carrot both above and below your hopefully still-intact finger!
Amazes and astonishes, and fulfills the "emotional content" rule quite easily. You may be able to get people to put money in the hat just by promising not to do this in front of them again. Finger insurance is included (just kidding, this is perfectly safe to perform).
You then hand both the guillotine frame and the blade back to the spectator to re-examine for a completely clean finish! Never fails to astonish!!! I have used this since 1959.
You get my full comedy routine on DVD and tips on how to milk this for fun and profit.