Grease stains on wool are often stubborn to remove. Professional dry cleaners can sometimes get good results, but the price can often be steep. Depending on the intensity of your stain, it is often possible to remove it on your own with a few household cleaning products. Before beginning the project, read the cleaning care label of your woolen garment to understand the manufacturer's cleaning and care recommendations.
Combine 1 ounce white distilled vinegar, 1 ounce liquid dish soap and 6 ounces of water in a cup. Vinegar is a natural stain lifter, and dish soap usually has strong de-greasing properties.
Moisten a white cloth with the solution.
Touch a hidden area of the jacket with the moist towel to test for colorfastness. If dye from the wool jacket transfers onto the moist cloth, consider using a professional cleaner, rather than removing the grease stain yourself. Otherwise you could end up with a discolored garment, even if you are able to remove the stain.
Dab the grease stain with a bit of the solution, just enough to lightly moisten it. Do this only if the fabric is colorfast.
Pat the moist area with the bristles of a dry paintbrush or toothbrush. This ensures that the solution completely soaks into the stain, rather than resting on top of the fabric; it is also better for the material than harshly rubbing the solution in with your cloth. Let the area set for about five minutes.
Blot the moist area with a dry, white cloth to absorb excess moisture, and to begin lifting the stain. It is important to always use a white cloth, as colored cloths can transfer dye onto your jacket. This can make the stain worse.
Moisten a fresh cloth with clean water. Blot the stained area with the moist cloth, and then again with the dry cloth. This is gentler and better for the fabric than rinsing.
Allow the jacket to dry, and check for stain removal. If the stain remains, begin the process again.