the lemon juice will start to dissolve the complex acetates (verdigris).

Follow up with the salt/vinegar/lemon juice/a bit of fine pumice .... thats how the 'ancients' did it.(nl)Throw in a bit of beeswax and olive oil and you have a short term preservative - seals it but will eventually turn 'brownish'.

.... forget the pumice, forget the beeswax, add feta cheese and you have greek salad dressing. Dont forget the ouzo!!!!