I'm not a mouse expert. I was reading a blog by one of the companies that makes some of those odor packets you buy. They say a common complaint to them is that someone will put out their product, then place baited traps or other food sources in the area, then complain that the mice still came. Similar to the moth ball video someone here posted: lots of sun flower seeds and some moth balls.
What the blog said was that the survival instinct of the mice is to eat food, no matter how bad the conditions are. Think of it this way: the mouse is very hungry and cold. It says "hey there is food in there but it smells like s--t. Oh well I'm eating". Or like if you were out in the hot sun doing yard work all day and someone said there was free beer in the overflowing outhouse.... your grabbing it.
I believe the moral of this story is to keep mice away you need to clean and remove all food sources from your trailer, and the nearby area. That means vacuuming up all the beer nuts and pretzels that are under the couch, scrubbing the stove so all the chilly party residue is gone, wiping down the pantry of all the oil, seasonings, etc that leaked out all year.
We do that to our trailer and then scatter around various brands of "peppermint" and "oil" packets. Two years and no mice, and the trailer smells nice. I'll report back in 10-15 years if it still is working.
Jim M.