I got a stubborn female switched over with a combination of "tough love" and trickery.
I got a bag of used mouse shavings from the pet store, and put an handful of it into the front part of her tub. Once she was actively hunting for the mouse that she smelled, I dropped in a rat and she hit it immediately, because she was expecting a mouse and a warm fuzzy creature entered her enclosure.
That's a really good idea, I hadn't thought of that. May have to give that one a try with my one stubborn mouser.