I have noticed a foul smell in my fifth wheel. All sinks have a pee trap, but the shower does not. Is there supposed to be a pee trap installed in the shower?
If the odor you smell is of rotten eggs (sulphur) when you nest use your rig, put some blue holding tank tank powder or liquid in the GREY tank in addition to the Black tank.
I only had that smell one time and this treatment works.