You peel 2 oranges, or in my case, 2 grapefruits, (just THE PEELS ONLY) and soak them in cheap white vinegar for 2 weeks in a tightly sealed mason jar. I put mine in a sunny window sill. This is for a household cleaner, but what I discovered is that this stuff takes iron stains off of the sink, faucets, showers and toilets and it works better than Lime Away and almost as good as Iron Out!!!! Non toxic too!
Siltech Innovative Windowsill Products Antique White 1/2 in. x 4-7/8 in. x 54 in. Acrylic Sanded Eased Edge Window Sill Moulding