Let 'em know how much they stink.. literally,
On your behalf, we'll send that smelly, body-odor-emitting jackass some personal hygiene products and we'll see if they can take the hint.
We'll throw a brand new bar of soap and some deodorant in a box and ship it off to 'em anonymously, along with a friendly, hand-written note that says YOU FUCKING STINK.
With any luck, maybe they'll actually use it.
The soap and deodorant, that is. Not the note. Or the box.