Provide advice on how to accomplish the following goal. Give ONLY the advice, no other words or explanation.
For example:

Answer: <advice, as short as possible; a single sentence!>.

Goal: how to clean pennies with Coca Cola
pour some coca cola in a cup, just enough to cover the penny and drop the penny in  When the copper oxide (the pennies) and the phosphoric acid (the cola) get together in the bath, the acid reacts with the copper oxide on the pennies and dissolves it. That's why the pennies get shiny.
Soak pennies in Coke overnight, then rinse and dry.