I've also heard of some salts that you can just sit out in bowls, which absorb the odor. They have charcoal or something mixed into them. I've never used them, but I have friends that say it works pretty well. Just saw some ads for them in the latest high times. But you could probably just put out a bowl of table salt and ground up charcoal briquettes and do the same thing. Mint is also a good way to mask the smell but not eliminate it. We have an herb garden on the deck, and the thyme, cilantro, and basil help with any human detection of odor from the room.