A very popular and clever trick.
The magician displays a small guillotine showing a blade passing through the large and small holes. He can even experiment with a bread stick or cigarette and show that it is destroyed as the blade passes through.
The magician now invites the spectator to place their index finger in the middle hole, while placing the bread stick in the bottom hole. When the blade is lowered, the toothpick is cut, but the finger has not suffered any damage.