In my previous rv, a travel trailer, I tried Irish Spring soap, dryer sheets, and Fresh Cab. None of those worked. And specifically, the mice built a nest in the Fresh Cab.
I finally tried oil of peppermint. I dropped three to six drops of the oil onto a cotton ball and put three cotton balls in little aluminum foil trays. I put these trays in every possible location where a mouse might go, particularly the under sink areas, drawers, cabinets, closets, etc. No mice! Not only did I have no nests, but there was no indication they were ever in those areas with the oil of peppermint. No indications of mice anywhere in the rig.
I endorse oil of peppermint. I use it now every winter. It is intense immediately after you open up your rig for the season, but by removing all of the little foil trays and opening windows and airing out your rig for a couple of hours, the scent is gone.