Sometimes people will train a dog to NOT do something by putting the bad behavior on cue. Then, the dog stops offering the behavior (apparently- I've never used this method) because it wasn't cued. So there's that...
...And then, maybe your girl just like smelling things. Have You considered doing K9 Nosework classes with her? Give her nose a job. Personally I think this is a great idea.
But again- if I had a dog that consistently and often repeated a behavior I didn't like, I might just give the first option a try to see if it really works or not. Try putting it on cue.
C-ATCH Pimg - DOB: 2/06, RATO, UJJ (x2), DJA, HIT, CA, CGC, High in Games, Reserve High in Standard- CPE Nationals 2014
RATCHX High Jinks vom Neuanfang - DOB 9/12 (Gotchya Day: 1/23/2013) CA, agility superstar in training