Which just goes to show how effective it will be.

There's a bit in Chuck Palanuiks "Fight Club" that isn't in the movie.

One of the characters is doing a catering job in a horrible and classist woman's mansion.

To teach her a lesson he leaves a note next to her very expensive perfume collection, comprised of 100s of bottles of designer perfume:

" I pissed in one of these bottles, good luck guessing which one"

She ends up throwing every bottle in the trash.

It's later revealed that the person didn't actually piss in a bottle at all.