Typically, the more expensive detergents will be best to use in this case. These detergents typically have more punch to remove those tougher stains. If the detergent process does not remove the stain then you can try rubbing alcohol. Use the same process as above and remember not to rub the stain! Let it soak and then rinse with warm water and dab.
The longer you leave the stain untreated, the harder it will be to remove.
Removing Fingernail Polish
Removing these stains takes some patience and skill. The best product to use is an acetone based fingernail polish remover. You should test the acetone on your carpet before you try this process. Good test spots are in a closet or somewhere that is not noticeable. When testing, place a small amount of acetone on your test area and let it sit for a few minutes. Then remove the acetone by blotting it out with a white towel. If there are no imperfections made from the acetone onto your test spot, you’ll now want to treat the stain directly.
You should use a dropper to apply the polish remover to the stain. Let the chemical soak, but not too long (most acetone based polish removers evaporate quickly). You should only let it sit long enough so that the polish starts to run. Then blot it with a white towel. The fingernail polish should lift off onto the towel and stain should be lightened. If the stain remains try the process again. Your last resort is to make a trip to your local store where they sell products that may work better. Be sure to follow the instructions carefully. With these types of stains I recommend contacting a professional carpet cleaning service.
Resource: Chem-Dry of Scottsdale