Vinegar is the superhero of stain removal (and cleaning in general!). Try these different formulas for homemade carpet cleaners to remove a variety of common stains: Rub light carpet stains with a mixture of 2 tablespoons salt dissolved in 1/2 cup white vinegar. Let the solution dry, then vacuum.
Coffee or Tea: try mixing 2 tablespoons hydrogen peroxide with 1 tablespoon dish soap. Blot the spill first, then apply the solution. Let it sit for a few seconds before carefully working the solution in with your fingers. Rinse the stain with water, blot, and repeat until the stain is removed.
Blood: Apply cold water or club soda, then blot with a clean cloth. Repeat until the stain is gone.
Dirt: Allow dirt to completely dry before treating. Scrape off as much as possible, then vacuum. Apply a detergent solution (like the DIY cleaner above). Let solution sit on stain for 10 minutes before blotting with a clean white cloth or paper towel.
Fat-based stains (butter, margarine, gravy, etc.): Use baking soda as a carpet cleaner for fatty stains. Sprinkle the stain with baking soda and let it sit for six hours. Vacuum and then blot with a cloth moistened with rubbing alcohol. You can also use a dry-solvent spot carpet cleaner following the label instructions.
Gum: Peel away as much gum as you can. Harden the remaining gum by placing a resealable plastic bag of ice cubes over it. Chip gum away with a spoon or dull knife. Vacuum and clean lingering stain with a dry-solvent carpet cleaner, following the label instructions.
Urine: Apply an enzymatic cleaner, available at pet supply stores or co-ops and other natural retailers.
Fat, Oil, and Wax: Place a paper towel or brown paper bag over the carpet and iron on a warm setting. The wax, fat, or oil should come up off the carpet and stick to the paper towel brown paper.