Smelly old books? Put each book in a plastic zip lock bag and put the bundle in the freezer for 24 hours. Take it out and let it thaw before you try to open the book and turn the pages. You may have to repeat the freezing and thawing. Freezing kills the organism that makes the old moldy smell. Don’t try this with books that have writing in ink or painted decorations that might “run” if wet.