Smelly car? Don't reach for air fresheners to deodorize your ride. All chemical air fresheners do is mask the odor, not neutralize whatever is making the unpleasant scent. Many used-car dealers employ freshly ground coffee beans to make the car smell nice. Just leave a bowl of coffee grinds in the car, and let the odors absorb through them. The coffee acts like a filter, cleaning the air and absorbing the smelly particles right into the grinds. The longer you let it sit, the better it will work.

Dirty grout lines between the tiles in your bathroom or kitchen can be a pain to clean. But all you have to do to keep them clean naturally is to use things you already have around the house. Pour hydrogen peroxide into a spray bottle and saturate the dirty grout. Let it sit for a few minutes, and use an old toothbrush to loosen the dirt, stains, mold or mildew. Wipe it up with a damp microfiber towel to reveal freshly clean grout. If you have stubborn stains, try a DIY paste made from white vinegar and baking soda, and use a brush to scrub away the grime.

The next time you're shopping at the grocery store, consider picking up a bottle of castile soap, a liquid soap that's made entirely out of vegetable-based ingredients and is 100 percent biodegradable. The eco-friendly soap has myriad uses beyond hand-washing; because it cuts through grease and dirt (without chemical sudsing agents), you can do a lot with it to keep your house sparkling clean. A few drops in a bucket of water creates an ideal floor cleaner. It also works well to lift stubborn stains set in clothes before washing them in the washing machine; it's great for degreasing pots and pans; and it can even be used to effectively and gently wash fingerprints off almost any surface.