What is the best way to: how to clean pennies with Coca Cola

Options are:
1). 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.
2). 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 dissolve
Answer:
1).