My ”Lincoln Log” home is 19 years old. The first few years after it was built, we had several water leaks around windows and sky lights (which has been rectified). We have ”lots” of water stains on the inside log walls and wish to get rid of them. Over the years we’ve tried several options (ie. bleach). Some of the stains are deep inside the wood fibers and sanding may not be an option. Is there a chemical on the market that would take care of our stain problems or do we have to sand.