Go to the fish tank section, get a package of those pre filled filters with activated carbon.
- If you are running the ac, slip one inside the duct.
- If you are running the fart fan, slip one between the screen and blades
- If you have a under microwave fan, slip one into section on top of the filter pad and fan
- Small solid, no porous bowl secured with museum wax, eat and apple, put a thin slice in the bowl, eat an orange, put a thin slice in the bowl. If in front of a sunny window, put whole anise star herb in the bowl. Flip them every time you walk by so they dry evenly and don't mold. Toss out or place on a tree branch when it no longer smells and the wild birds will eat them.
All are non mechanical and cheap enough to toss at the end of each month. Don't purchase normal carbon, get the activated carbon. If you are crafty, you can bake the activated carbon to reactivate it, but that puts all the sour smells it gathered back into your coach while baking.