You can force the air out the on thanksgiving day. Open a window upstairs, put a big fan in it pointing outside, then crack a couple windows downstairs. This will create a negative draw so house air goes outside. Than before every comes over close it up. And use candles. If the odor crepes up they won't be able to tell. To me ona gel was always kinda strong and makes it seem like your trying to cover something up.
put an exhaust fan (small fan, or a box fan) in a window to blow air outdoors (preferably in a window in or close to the grow room. crack another window in another room upstairs to get air flow moving into and then out of the grow room so the smell doesn't come out. use a air freshener or plug in upstairs as well if you can. (yep, like the guy above me said didn't read whole thread first)
Some people suggested that you just be honest with your extended family. Fuck that. Seal up the grow room, put a gate at the bottom of the stairs as a physical deterrent, then do what another poster said and simmer some cinnamon sticks in water on the stove. I think the smell of the cinnamon, plus all the food from thanksgiving, will definitely cover up the smell.
Very well, my sister bought some cinnamon thing and I used a fan to push air out the window. I also put a baby gate blocking the upstairs. My cousin who's a cop came and not a word was said but now my house is back to that marijuana smell we all love
I had my own scare this past weekend.....brother in law and his family showed up as a surprise (!) for thanksgiving weekend. Needless to say the grow box was undergoing some renovations so there was a little odor in the air. At one point he went to the general area it was in but didn't see anything. Close call.