Save a mildewed book
Found mildew around the edge of a childhood classic you adored? If it's a mild case, sprinkle baking soda lightly between the pages, then put the book in a paper bag and dust the outside with more baking soda. Let it sit for several days, then remove, shake out, and dust off the baking soda, and let the book get a shot of bright sunlight. It doesn't remove mildew marks, but if you store it in a dry place, no more mildew will grow.