One of the many gags with "Knife through spectator's Jacket" is the security chip gag. That little plastic chip thing that clothing is secured with in malls. It is secretly attached to the jacket. I found this to be not easy sometimes. So I created an alternative gag. And I seem to be the only one doing that.
Basically palmed in your hand you have a little transparent bag of cannabis. Mine is actually tea, glued on little wooden pellets. Just take the jacket with the hand that palms the little bag and drop it on the floor. It will be noticed. You pick it up and do your gag.
And although I don't do drugs: "Legalize It!"
Btw: Thumbtips are great for smuggling drugs. Fingertips are even better. They never seem to check the very end of your hands.