Soak a clean cloth in turpentine.
Rub the turpentine over the wood stain until the mark is gone. If the mark is stubborn, hold the soaked cloth over the wood stain until it softens.
Scrub the stain if you can still see it. Use a stiff, nylon-bristled brush.
Mix ¼ cup trisodium phosphate with 1 quart water.
Dip a cloth into the solution and rub it over the area to neutralize the turpentine.
Dry the porcelain completely with a clean cloth.