Or get some super hot chilis and brush a couple of old harps down with the oil real good and then "accidentally" leave a them their when you leave.
j/k
Get a harp (is that a harmonica?) and slice a few habaneros with it. Get that oil all over!!! (Of course, wear gloves and wash wll after)
Set it on the table at rehearsal, and tell them 'Whatever you do, don't stick this one in your $^%#!'
Of course, they'll do it!
Ooooweeeeee!
Plus, getting that stuff on their fingers.....then their eyes!
Oh, think of the joy!
