The Joy of Metal Clay: When shot gets dirty!

I just tumbled some silver metal clay pieces overnight last night to find all of my pieces completely black this morning!!!! Panic. Here are two of the pieces with black deposits on the front. I guess with the business of summer I had not cleaned my shot in a while. It was surprising to me how filthy it was and the horrific deposits on my beautiful silver. I took the shot out and put it in a colander with soap and washed and rinsed several times. I also cleaned to barrel with soap and water. Another way I rinse and …