I have a dark grey/marble effect laminate countertop in my kitchen. We made the mistake of putting our dish rack on it without anything underneath to catch the water and now the whole side of the countertop next to the sink is whitish from calcium and other mineral deposits. We've tried everything (cleaning products, Lime-a-way, all types of calcium-removing products, etc.). We don't want to scrub too hard for fear of scratching the surface and making it worse. Is there a way to safely remove the hard water stain?