Apply white vinegar to a washcloth to dampen it.
Blot the Sharpie stain with the washcloth.
Combine two parts vinegar with three parts cornstarch to create a paste.
Rub the paste over the Sharpie stain and let it dry completely.
Vacuum the dry paste off the couch.
Pour rubbing alcohol onto a clean sponge.
Blot the rubbing alcohol over the Sharpie stain.
Soak a washcloth in clean water. Blot the couch to remove the rubbing alcohol.
Blot the stain with a dry towel to absorb the liquid from the couch.
Combine 1 tablespoon of liquid dish detergent and 1 tablespoon of white vinegar in a bowl. Add 2 cups of cool water and stir to mix the ingredients.
Place a washcloth in the solution to dampen it.
Blot the washcloth over the Sharpie stain.
Let the solution rest on the stain for 30 minutes. Blot the stain every five minutes with paper towels.
Flush the area with clean water. Blot with a towel to absorb the excess moisture.