Have some of the Jackass crew poop in a purse. Or use elephant poop....and fill the bottom of the purse. Cover the poop with makeup, tissues, personal items, etc. that you'd normally find in a purse. Then set in on a semi-busy sidewalk.
(Making it a Coach purse would attract more attention I think.)
When "curious" people walk by they'll probably check the purse for money, but instead they get a disgusting surprise!! After a few people have "gotten their hands dirty" you could have Spike Jones dressed as his old lady persona to catch a final victim in the act. He could say something like "Oh good, you found my purse!" "Thank you young man/lady" hahaha!