Jake, you can clean some buttons with a dry soft bristle toothbrush depending on what type of soil they were found in. Our Georgia red clay will eat them up. Be careful because sometimes you can actually punch the center out with a thumb or finger if pressed too hard depending on the condition or the fragility of the button. This is true with Eagle buttons. I've seen this happen before and it's heartbreaking. You can also try getting an old jar and adding white vinegar along with some arm & hammer baking soda.