Breaking the mouser of mice

What's more thrilling than getting a mouser to take a rat? Taking two rats!

Recently acquired a lovely 1600g pinstripe adult female that is addicted to mice. I've tried scenting the rats before with no luck, offering mouse sized rats, mouse bedding in the cage before offering a rat, and tossing in a rat after she's had a mouse and hungry for anything - and she just would not break.

While at the reptile shop today, the manager scented a small rat for me by washing it with Dawn soap first - what??? But it worked, and my pin girl was so pumped up after that she took another rat, unscented, no problem.

I understand the concept of removing the rat smell first but I'm not totally comfortable with the idea of washing a rodent with dish soap, though it seemed to have done the trick.

Your thoughts?

It should be fine. I wash out my water bowls with dish soap every other time I change the water. You just have to rinse it out well afterwards, bowl or rat.