A big bowl of white vinegar in the smelliest part of the room for a day will help, too. It absorbs the odors and neutralizes them without adding perfumes or anything toxic.

I also agree with a hanging bag of dessicant if you are going to be in the same room for multiple days. That stuff actually works pretty well in small spaces (useless in a big basement though!).

I wonder if they make small, personal-sized dehumidifiers?