The best way to remove a chocolate stain is by using techniques that break down oils and milk solids, and by laundering the item carefully so the stain doesn't set. How you do this will depend on whether the stain is on upholstery or clothing, and what type of fabric is involved. Prompt treatment will help prevent chocolate from marring the item permanently.
If the chocolate stain results from solids like candy or ice cream, you should first gently remove any excess. Be careful not to spread it around or you will have a much bigger spot. Generally, using a spoon is the easiest way to scrape it up, and the blunt edge won't tear clothing or upholstery. A couch or cushion cover may be thick enough so the stain stays on top instead of soaking through.
Let any stain removers activate for a short time; you can dab at the chocolate stain with a clean white cloth, until you have gotten as much as possible off the fabric. Most cleaning experts recommend a gentle touch. It's best to do this from the wrong side if the stain has absorbed, so you're not pushing it back into the fabric.
A chocolate stain on carpet can be especially troublesome if it gets compressed into the fibers. Liquid dishwashing detergent in warm water can usually remove a fresh stain if you get to it before someone steps on it. If that doesn't work, a solution of 1 part household ammonia to 16 parts water can be used instead. Be very careful not to mix ammonia with bleach or dangerous chlorine gas will result.
You may use a stain removal stick or liquid to loosen a chocolate stain on most clothing before laundering. Repeat any pre-treatment steps you took if it lingers. Once the stain is gone, it should be safe to dry the item. If you take your garment to be professionally cleaned, point out the chocolate stain so the cleaners can eliminate it, or the solvent’s interaction with sugars in the stain may make it worse.
Dry clean-only clothing can often be successfully treated at home by blotting carefully with a little water or products formulated for them. Special dry clean solvents are sold in discount and hardware stores, but many people don’t like using them because they are toxic. Home dry cleaning kits contain a water-based stain remover and special pads to place under the spot. If you get a chocolate stain on a dry clean-only garment, make sure you spot test the remover in an inconspicuous place first.