Ensure that your couch is completely dry. If you’ve suffered a house fire, the water used to extinguish the blaze may have soaked your couch. Dehumidifiers and fans will dry your couch and help prevent the growth of mold and mildew.
Sprinkle the baking soda or cornstarch over the stained area on your couch, but do not rub it in. Touching the soot will set the stain.
Let the baking soda or cornstarch sit undisturbed for one hour or more.
Vacuum the couch. Remove any attachments or brushes from your vacuum cleaner, and hold the nozzle slightly above the couch as you vacuum. If your vacuum touches the couch, it can work the stain into the fabric. Once you've vacuumed the couch, most of the soot has been removed and you can work on removing the charcoal and soot stains.
Prepare your cleaning solution by mixing 2 cups of water with 1 tablespoon of dishwashing liquid.
Wet a clean white cloth with the cleaning solution and use it to sponge the stain. Blot the stain until all of the liquid has been absorbed.
Continue sponging and blotting the affected areas until the stain is gone.
Wet another clean white cloth with plain water. Sponge the previously stained areas with water.
Blot the couch with a dry white cloth to absorb the water.