That is a quite simple instructable, on how to polish metal using things found in your kitchen .
It turns to be as good as commercial polish products, but is cheaper and environmentally friendly

Step 1: Materials

1) Lemon

2) Baking Soda

3) Piece of Cloth

Step 2: Squeeze, Sprinkle , Mix and Rub

1) Squeeze one lemon on the surface that you want to polish

2) Sprinkle 02 or 03 soup spoon of baking soda and mix with lemon with your hands

3) Let this mixture dry for 1 hour

4) Rub hard with a piece of cloth and you done

Below pictures of polished pieces of an antique chevrolet 1952 using this method .