Anyone had any success removing black discolouration/black stains from their hardwood floors. Have just sanded mine to be pale timber, but about 1-20 still have black discolouration/stains, even with extensive, repeated sanding with both 40 and 32 grit sandpaper … the solutions I have researched online are really conflicting, from white vinegar to baking soda, to mineral spirits - to hydrogen peroxide to chloride bleach. Really don’t want to have to replace them. Would love to hear what may have worked for others, who have had the same issue with their floorboards - and were successful in removing black discolouration/black stains without damaging their boards. Thanks so much for any suggestions.