BEFORE you use odoban take a whiff of it first!
It is a POWERFUL smell that does NOT ever go away. Your RV will smell like the local dog pound. IMHO I would never use that stuff anywhere near or in my home or RV.
There is all different types of lime but most of them are caustic and should NOT be used around pets.
http://homeguides.sfgate.com/hydrated-lime-hurt-animals-87490.htmlI travel with four dogs and there is never any smells. I use a patio mat where they go. It is picked up immediately. And I spray down the mat often with dawn soap and water. No smells.
In your case the poop, even though you are picking it up, there are still parts of it on the blades of grass and down in the grass and over time that is most likely where the smell is coming from.