Dishwashing detergent or ammonia can get rid of chocolate stains on washable fabrics such as cotton, nylon or spandex. Flushing the stain with club soda also helps to get a chocolate stain off of clothing, but usually soap or other cleaner is also necessary.
Soap and water is often best to remove a chocolate stain from surfaces such as glass, ceramic or vinyl, and washing soda and detergent is the best choice to remove a chocolate stain from surfaces such as marble.
For chocolate stains on a carpet, Spot Shot Carpet Stain Remover works well. If it remains, ammonia and hydrogen peroxide may also work.