When making crafts with coins, here's how to clean them: make a scrub out of white vinegar and baking soda.When you mix the two it bubbles up so you may want to mix it over the kitchen sink. Make a juicy paste, rub it on the pennies and let it sit a few minutes. Come back with an old toothbrush and give ‘em a scrub. The penny on the left and the right are the same penny. Crazy, huh?