gravity bongs are not really good for odour control; the smaller the piece/bowl, the better. 7 hours should be plenty of time if you know what you're doing.

Here's the general process:

1. Close and lock the door. Place a towel or similar object in front of the gap at the bottom to prevent smelly air from escaping your room.

2. Open the window. If you have a non-ceiling fan, aim it out the window and put it on full blast. Note: depending on your airflow situation, if you use a fan, you may not want to put the towel under the door in step 1. The theory here is that air will be pulled into your room from outside and out the window - constant airflow, and since air is coming in the room and not out of it through the space beneath the door, no smells escape. In practice, this works sometimes, depending on the airflow in the room.

3. (Optional) Make a spoof. A spoof consists of some sort of tube (usually a toilet paper / paper towel roll or a plastic bottle with one end partially or entirely cut away) stuffed with those sheets you put in the dryer to make the clothes smell fresh (what are they called? just dryer sheets? not sure). Breathing smoke through the spoof (And into the fan to be pulled out the window, if you have one) makes it smell more like fresh laundry and less like illegal drugs, which is good.

4. Smoke! Avoid using techniques that cause a lot of smoke to escape from the bowl/chamber/whatever into the air. Not only is this a waste of weed, it can also get you busted due to the smell. Obviously, direct your lungfuls of smoke toward the window, through a spoof if you choose to use one.

5. Defunkify. I recommend an odour neutraliser (i.e. something that gets rid of existing smells rather than adding its own). Febreeze doesn't actually work well; if you spray a sane amount, it doesn't cover the smell of smoke entirely, and if you spray enough to fully banish the pot smell, it will be obvious that something's up since the room will reek to high heavens of febreeze. Axe works fairly well, particularly if you wear it normally so it will be a familiar scent. If you can find it, this stuff called Ozium is incredible - way better than anything I've ever tried.

Anyway, 7 hours should be enough time if you do even a little of what I suggested.
Solistus Reviewed by Solistus on . Is this safe? I was thinking of smoking in my room before school, and was wondering whether or not the smell would be gone by the time my mom comes home from work (7 hrs. after my session)? I am already going to open the windows spray down the room with febreeze and axe but are there any tricks anyone knows about that could help me get the smell out (besides doob tubes)? I am planning on using a gravity bong by the way. Rating: 5