If a spill happens, blot—do not rub—stain with a paper or cloth towel. If the stain has solid or dried matter in it, remove as best you can with a dull knife.
Take the rug to a dry cleaner to safely remove the stain—even if it is a very old rug. If that isn’t an option, mix up a solution of two cups lukewarm water, ¼ cup white vinegar, and liquid dish soap.
Most Oriental rugs are acid-resistant, so vinegar should remove the dirt but not the dye. Test for colorfastness by blotting an inconspicuous area with the solution on a white towel. Be careful—if color from the rug comes off on the towel, do not use this solution. Take the rug to the dry cleaner.
If you want to clean it yourself, place an old towel under the stained area in case the water soaks through.
Sponge solution on stained area, moving in the direction of the nap.