A sanding sponge is a useful tool to have around, helping you smooth surfaces while offering extra advantages over conventional sandpaper. It works well for sanding drywall, scrubbing corners ...

This Old House advises using: a coarse, 60-grit sandpaper or sanding sponge to abrade the discolored wood, but don’t try to get rid of it entirely: Sanding too much in one spot will create a dip.