Heavy,
You're in for a good time. And don't worry, as foul as it smells, it surprisingly comes completely off, scent and all, with a little soap and water so if some ends up on your fingers just hold your breath and head for the nearest bathroom sink.
So prank update...
Last Friday I tried to get my boss. He's a good dude and likes to play pranks as well, also a bammer. Me and my buddy waited until his office was empty around 11:30am (lunch time). Then I found a funny image of a scratch and sniff turd with a smiley face, printed it off, sprayed it just once, then dropped it on his desk.
We figured he'd get back from lunch, see it, be real hesitant but curiosity would get the best of him and he'd take a whiff. So we swing by around 12:45 and notice the lights on and someone in there. We walk in to find someone else sitting at his desk. Coincidentally its another manager who is a real d*ck. He's never been over either of us but we've both worked with him before on a joint project and neither of us likes him very much. Anyway he's sitting there and the scratch and sniff is in his trash can. I ask him why he was in Don's office and he said the two of them had switched buildings 2 days prior. We said "oh, okay" and walked out. Got outside and busted out laughing realizing we'd just pranked the resident a-hole without even trying to. No way that guy didn't smell that nasty crap.
Later we tried again to get our boss once we found his new location but it didn't work out as well as we hoped, he was wise to the gag and didn't take the bait. But regardless, punking that douchebag in Don's old office was victory enough.