Dissolve a box of baking soda into a gallon of water. Stick two pieces of thick solid copper wire into the solution, apply DC current. After a long time, the solution will turn a really dark blue. Remove the now black piece of copper wire and replace it with something made of steel. Replace the other piece of wire (which has probably disappeared) with new copper wire. Don't shock yourself, it hurts. Make sure to spill the solution everywhere.