Who doesn't have a bunch of old change laying around their car, desk and night stand? I collected up a few pennies and decided I was going to clean them of years of gunk. Looks like it didn't help. Change somehow goes through an aging process that is unique and completely random. Much of the dirt and grime on loose change is there to stay.
I remember as a child that we would take pennies and shine them with erasers. I didn't have a pencil and keyboards don't currently have erasers, so I will just leave that one alone. Either way it made a great picture and allowed me to say that I brought clean change to the coast of Mississippi.