My husband just refinished our basement. Our beautiful stairs were put in a while back and I noticed a spot on one step. I tried to clean it with water and soilax and now I have about 1/3 of the step that is dark and the other 2/3 is fine. They are not treated as of yet so I tried to clean the wood directly. I would like to try and fix the problem so that he doesn't have something else added onto his to-do list. Is there something I could try? Feeling really really guilty and would love some advice. Thanks!