Oilskin is a fabric used for coats such as Australian dusters and northwestern mackinaw-style jackets. Oilskin is a waxed cotton and is waterproofed when the wax is on the fabric. The fabric is stout and withstands the elements with aplomb. Oilskin does get dirty and requires a special method of washing and cleaning to ensure the longevity of the fabric.
Fill the tub or sink with cold water and add one capful of the mild, woolen-sensitive detergent. Stir the water to develop suds.
Wipe off the coat to remove any dust or dirt. Place it in the tub. Soak the coat in the soapy water overnight.
Take the coat out and place it on a hanger.
Take the coat outdoors on a hot day. Expose it to direct sunlight during the hottest part of the day, if possible. Let the sun heat the coat to make it supple. Dip a cloth into the oilskin wax and apply it to the outside of the coat. Work it into the coat, using a circular motion.
Apply the wax, using the cloth and a hair dryer if you do not live where it is sunny and warm. Heat the specific area of the coat with the hair dryer and wipe the wax onto the heated area.