How do you get yellow smoke stains from cigarettes out of floors?

Even for old discolored wood floors this recipe is Excellent: In a pail put approx. 1/4 cup of Witch Hazel (can be bought at any drug store) and a couple of squirts of Dawn dish soup. Take very SOFT steel wool, gently scrub and wipe up with clean warm water and towel. It will come so clean you'll probably have to do the whole floor. LOL Marcy