This trick actually fooled almost everyone I showed it to, but I'm sorry to report that someone
caught on and decided to ruin the trick for everyone else (she took the knife away from me under the
pretense of "washing it" - she continued to make the rest of the visit unbearable on purpose, so she
knew what she was doing). My advice would be not to allow anyone near you while you're doing this,
period. I was across the room from the rest of the group, but the person ran up to me and grabbed
the knife from me.
My next trick will be to make her disappear.