Fresh Cab works great.
https://www.earthkind.com/product/fresh-cab-rodent-repellent/Was introduced to it by a friend whose family has a large farming operation in Iowa. They use it for all of their winter storage and have no issues with rodents. I used it in the camper while in NM and use it here for the camper, and in the shed with the yard tractor and ATV, so far all has been well.
