Experts recommend replacing an open box of baking soda in your refrigerator about once a month. When you do replace the box, don't throw away the old baking soda. Instead, sprinkle it in the shower; wipe it up with a sponge, and your shower will be sparkling clean. You can also get your outdoor grill clean by using a mix of baking soda and water to scrub off the crusty, grimy mess. And if you have old books, sprinkle some between the pages and place it in a plastic bag; wait a few weeks, and you'll have a fresh, mildew-free tome.