detergent? to just wash/wipe it off ...If still no luck with liquid cleaners...then ultimately you will need to use a very fine mesh steel wool like 0000,,,and then lightly/gently rub the fine steel wool across the stain ..the steel wool will act like sandpaper so use light pressure....and just buff the stain out. it will remove the polyeurethane coating and maybe even some of the wood stain...!! then you may need to go back over the spot using a soft cloth and touch up the stain and the polyeurethane. good luck LJ