Deodorize the hardcover book by first searching for any mildew spots on the pages and then covering them with cornstarch. Let the book sit for 24 hours. Shake out as much of the cornstarch as you can.
Use a magnetic dusting cloth, such as a Swiffer, to pick up the leftover cornstarch as well as any excess dust or dirt from the pages. Remove any marks or stains from the pages with a white vinyl eraser.
Pour rubbing alcohol into a cotton ball and squeeze out until it is no longer dripping. Never pour the alcohol directly onto the hard cover of the book. Gently wipe the hard cover of the book down with the cotton ball, using small circular motions. Use a dry cotton ball to buff away any excess moisture the rubbing alcohol leaves behind.