Combine ½ tsp. of washing soda with ½ tsp. detergent for each pound of rug material and wash the rug in hot water. Rinse well in cold water. Place the rug in a bathtub and close the drain or set the rug in another large tub.
Pour two quarts of cool water into a large pan made of stainless steel. Add ½ cup of washing soda, 1 tsp. of liquid detergent and 3 quarts of 3 percent hydrogen peroxide to the pan. Stir the ingredients together until they are fully combined. Heat the solution to about 130 degrees Fahrenheit.
Carefully pour the contents of the pan into the tub.
Set the rug, with the fabric side facing down, on the surface of the water in the tub. Use a wooden spoon to push down on the carpet until it is submerged into the solution. Fill 4 large containers, such as jars, pots or bowls, with water and place them on the rug to weigh it down. Leave the rug in the solution for 24 hours.
Drain the tub. Rinse the rug off by holding it under warm water. Fill a bucket with 1 gallon of water and add 2/3 cup of distilled white vinegar. Spread the rug flat in the tub. Pour the water and vinegar solution over the rug. Allow the rug to sit in the solution for 10 minutes. Rinse the rug in warm water.
Gently squeeze the rug to wring out any excess water. Hang the rug up until it has fully dried.