So while I was visiting my parents I managed to find some beautiful copper cookware pieces in their basement that they weren’t using and let me have. However, they have been sitting in the basement for a very long time. Using some lemon and salt, I managed to polish this egg beating bowl quite nicely, except there must have been a leak at some point and you can see the green where some water dripped in it and stayed – green copper is toxic – no amount of lemon juice or vinegar seems to be dissolving it for it to come off, and scrubbing has yielded little success – any tips? I’d really like to restore these pieces to functional condition and use them in my kitchen