That solarvent looks interesting...
Since you are fulltimer, this likely won't fit your situation. What we found is we would put in tank treatment right after dumping on way home from a weekend camping. It would be several weeks before next trip and the treatment seemed to wear off. Now, we don't add treatment until day we head out. The driving seems to stir it around and cut odor.
Another possible issue is if water in your toilet bowl leaks down or evaporates from long term storage. You need a little water left in bowl to seal off odors.