I sympathize. No smoking at work, right? Then there should be no gum-chewing and no Patchouli-wearing. Unless you're a carney, then no one cares how gross you can be. And it really sounds like they may be chewing extra-monstery out of spite for all the times you've asked nicely. They were gross before; now they're a gross asshole.
You're going to force it to read this post?