In 2005 I complained about my Astralux kitchen sink in my new house and the hard job it is getting it clean, compared to stainless steel, ceramic or enamel.
On Saturday I happened to see a new product in Wilkinson called Astonish Oven and Cookware Cleaner. This is a mildy abrasive paste in a tub, not unlike the stuff I once used to lap in valves. But it is the *first* cleaning product that actually works on the sink to remove the really stubborn stains! I actually purchased the product for cleaning stainless steel pots and pans, then I thought I'd just try a little on the sink, with one of those rough scouring pads (not Brillo pads!) and it's ruddy hard work, but there *is* a definite improvement.
MM