Sounds good, but don't you have grease everywhere after the ride?
Boss I used to work for told me a story about getting even with a co-worker who pissed him off. He filled a syringe with axle grease and would put tiny little dabs of the stuff everywhere in the guys workspace. A little dab on his chair, under the armrests, on his lunch bag in the fridge, his car door handle etc. Not a lot, and not on a regular basis, a little here and there. Drove the guy nuts, had grease everywhere and couldn't figure out where it was coming from.
Sounds like this kind of situation in the making.