I just ran across this great article on Homestead.org about Natural Alternatives to Costly Chemical Household Products.  This article not only covers the normal kitchen and  bath cleaners you normally find but it also covers rust cleaner, paintbrushes, metal cleaners, tar removal, and automotive care.

Here is a sample of what you will find:

Automotive Care

Natural Engine Degreaser:  Dissolve one-quarter cup of washing soda into one gallon of warm water, pour on engine areas that need degreasing.  Rinse thoroughly.  Excess should not be stored – discard all leftovers.

Battery Cleaner (Removes built-up acid):  Sprinkle baking soda on the battery terminals.  Spritz with water to dampen.  Let sit for about one hour.  Sponge off with water.  Air dry.

Winter Windshield Solution:  When you leave your car outside in winter, mix three parts vinegar to one part water and coat your windshield with the solution.  This will keep your windshield free of frost and ice.

Ink Stains:  Use a non-aerosol hair spray to remove ink stains.

Jewelry Cleaner:  Baking soda is safe and effective when it comes to cleaning jewelry.  Use a paste of baking soda and peroxide to clean build-up and dirt off or your jewelry.  It gets rid of dirt, grime and body oils to leave your jewelry shining and looking new.

Metal Cleaner:  Clean copper, brass, pewter, or bronze easily with a simple mixture.  Dissolve one teaspoon of salt in one cup of vinegar, add enough flour to make a paste.  Apply the paste to the metal and allow it to sit for fifteen minutes to one hour.  Rinse with warm water and polish dry.

Paintbrushes:  Soften hard paintbrushes in hot vinegar for a few minutes.  Then wash paintbrush in soap and warm water and let air-dry.