I'm not worried about smell yet, but I know this is a soon to be problem I've been looking for something, and unfortunately I ventilation system is out of the question. I've been thinking about http://www.inetlocate.com/viewsales2.asp?H3845=1597&5539=9076&912JH=9&36&728MM anyone have experience with these?
honestly i would say something like that just isnt even worth it. first of all... its really not gonna cover up the smell that much, what happens inbetween those 15 minutes? lol and secondly you dont really know how your plants are going to react, it could stunt growth, or worse cause death. *note places that use this stuff in green houses, also have ventilation to get it back out and good air back in.