How to eliminate odor in a room?

I don't like to use an air freshener or products like Fabreeze. I don't like those. I need to get rid of odor quick! Friends are coming on Tuesday. How should I get rid of stench? I've had the window opened with the fan on for days, and nothing. I think it might be cat puke smell, though I'm not sure. I would not care to use natural common things like a spice, and I wouldn't care to use perfume.