Just a little update. Well, we have tried everything mention in the previous post to eliminate the smell of moisture with no success but this little gizmo
After 24H in the camper at max power the smell is gone! We now have an after rain fresh sent in the camper. The only thing is that you can not be in the camper whiles it is plugged in at max level. Maybe at the minimum, but I wouldn't do it. To much conflicting report about the long term effect on human an pet.
Something to try if you tried everything else.
Cheers, Steve