The only time that we have a problem with odor is when the toilet is flushed while driving. I think the venture cap would solve that. The only time that it would be effective to pull odors out is when you are flushing. And that is when you want it to work.
David, Sherry and our three fur kids, Nicholas, Finnegan and Bentley
2013 Coachmen Encounter 36BH
2014 Honda CR-V/ Blue Ox Patriot II