My 96 year old Mother gave me a treasured pot which I believe is hammered aluminum. She has had it for over 60 years. My husband put it in the dishwasher. The inside seems fine but the outside has all the black flaking off. It feels gritty. Can I still use the pot? Should I try to get all the black off of it? I have been looking at the cleaning/restoring pages on this site but I'm not sure which ones apply. Thanks for your help! Mary