I usually try to think "outside of the box", so the other day I decided to see what effect the dishwasher would have on some the dirtier coins. My dishwasher comes with this little basket that you use for smaller items so I decided to put the some clad in there and see what would happen when I ran it with the dishes. The results are mixed. The coins did not get completely clean, but some did get pretty clean in certain areas. I imagine that a more powerful dishwasher might work better...something that would really swish the coins around. When I do it again I am going to try it on the top rack. If anyone trys this and gets better results post it.