I agree with Henry. There is a product with enzymes in it that does take away the smell. It comes under several different brands names - just make sure it has the enzymes in it. You have to remember that cats have excellent smelling abilities and even if it smells like it's gone with regular soap and water - it's not and any other cat will know it also. Since you plan to rent the mobile out again - I'd probably polyurethane the solid floor also. I'd rather be safe than sorry, and get a large pet deposit from the next renters. Please remember - not all cats are bad. Out of my four indoor cats - only one occassionally urinates outside the litter box (and I have the boxes on continous vinyl flooring.