If the moth ball smell won't go away, there are probably still moth balls somewhere. Gotta get rid of them before the smell will quit.
If you are sure they are all gone, try the Odor Medic or similar. But moth ball smell tends to get into fabrics and carpets, so it takes awhile. Cleaning the fabrics and carpets might help.
Former owner of 2004 American Tradition and several other RVs
Home is West Palm Beach, FL