My dog is disgusting, anyone else?

This is my 4-year-old bichon / cockapoo mix. She has one really bad habit and I'm not sure how to break her of it. She loves to roll in disgusting things.

In the past couple of weeks she has rolled in dead fish, a dead rat, and then today she rolled in vomit. I'm at a loss of what to do. We have her on leash but she quickly rolls or at least tries to roll whenever she finds something disgusting. anyone else's dog do this?