Have stainless steel exterior window sills, which were quite stained and unsightly after five years. I have tried this with very expensive cleaning agents to clean, while the windowsills were always greasy.
From a chef I got was the tip to try it with Viennese chalk. The tip was worth gold. The window sills are like new, and a real human price. These Viennese lime is still 100% environmentally friendly.
