Grapefruit-seed extract: Add a few drops to water in a spray bottle for an odorless way to kill mold and mildew.
Lemon juice: Use as a bleaching agent on clothing, and to remove grease from your stove and countertops. Add 2 Tbsp lemon juice to 10 drops of (real) lemon oil and a few drops of jojoba oil to clean and polish wood furniture.
Olive oil: Use to lubricate and polish wood furniture (three parts olive oil to one part vinegar; or two parts olive oil with one part lemon juice). As an alternative, you can use linseed oil.
Potatoes: Halved potatoes can remove rust from baking pans or tinware – follow with a salt scrub or dip the potato in salt before scrubbing.
Tea tree oil: Can be added to vinegar/water solutions for its antibacterial properties. Use it to kill mold and mildew, and on kitchen and bathroom surfaces instead of chemical products. Add 50 drops to a bucket of water to clean countertops and tile floors. You can combine it with vinegar.