Chalk Dehumidifier - A bundle of chalk hung in a closet will absorb extra moisture and keep clothing fresh and dry, and takes up much less room than an electric dehumidifier.
10 Best Houseplants to Improve Indoor Air Quality - this one actually cites the nasa study.
Hang a bundle of chalk in the closet to keep everything fresh and dry. The chalk absorbs excess moisture - a thrifty alternative to an electric dehumidifier! Household Tips for Every Room in your Home