Things You'll Need
Instructions
Fill your waterproof box with coins so it is about three-quarters full.
Pour vinegar into the box until the liquid level reaches just past the height of the coins.
Add a tablespoon of salt to the liquid.
Close the lid of the box.
Shake the box gently to agitate the solution. The salt will scrub the coins and the vinegar will dissolve deposits. Every few minutes, inspect the coins to check the progress. Eventually the solution will make the coins bright and shiny.