Here's something I wish I had found before half our staff flew off on a surfing trip: a water soluble bikini.
Sure, it would have only made sense as water soluble bathing trunks for everyone but Jesus, who is European and therefore wears a bikini, but still, the idea holds up. You give them to your unsuspecting friends who then go in the water. Within three minutes, they disintegrate, leaving your friend humiliated and terrified. Heeee-larious! [RevengeShop]