Haven't read all the posts, but here is what I do down at the farm to keep the critters under control. I've got a 5 gallon plastic bucked that I put 1 gal. of RV antifreeze in. I drilled a hole on opposite sides of the bucket for a rod to go through, then I took a pop can and drilled a hole in each end & inserted a rod through it to span the top of the bucket. Also I put some wire on the rod on each end of the can & rod to keep then from sliding. I have a small stick running from the floor to the top of the bucket, with small nails tacked on the top end to keep it from falling off the bucket, I've got the stick placed near the rod. I'll coat the pop can with peanut butter. Mouse smells the peanut butter, finds the stick, climbs up bucket, sees the pop can with peanut butter walks across the rod to the pop can. When he gets on the pop can it'll roll dumping him into the RV antifreeze & he takes a final swim.
It's easy & cheap to make, it requires little maintenance, there is no mess. I've got a minnow net near the bucket so when I'm down there I can dip them out easily. Works for me! In an RV, you might need 2, one in the living area, & 1 in the basement. This is the 2nd year of doing this & haven't had near the mouse damage in years past. Keep them going year round, but in the summer I've got water in the bucket instead of RV anti freeze.