I have 2 small areas on my T&G pine ceiling that have been stained by a water leak. The T&G serves as the floor of my second story as well as the exposed ceiling of my first floor. I've fixed the leak, but now I need to fix/conceal the water damage. There's a very small area that is gray and rotted. If I sand these small areas, it will be obvious. Is there a wood cleaner suitable for indoor use that could lift the majority of the stains?