We've had mice in our old hunting camp for decades and have tried various things like peppermint oil and Fresh Cab. If you read reviews of Fresh Cab you'll find it's about equally split between "works great!" and "doesn't work at all". Same with peppermint oil and many other folk remedies. There is more than one species of mouse, and it's my belief that some of these products will work wonderfully on certain species and not at all on others. Not at all was the result we got in the cabin with Fresh Cab and peppermint oil. Just kept trapping.
In my camper, I've left traps in it full time and had no mice whatsoever until a few weeks ago I caught two. No more since then. I think when I was going in and out the screen door (in my yard), I sort of swung it shut and it bounced open and I didn't notice it for a while.