Hi there I was taught an old trick many years ago- it was used by Georgian Butlers to clean the family silver & works on the same principle. You need some aluminium cooking foil, washing crystals & boiling water. Great for silver, brass, copper as well as steel & iron no matter how cruddy. It gets into all the nooks & crannies too. I then wash it in warm soapy water, if still cruddy I might rub with 0000 wire wool & repeat. Then a polish with Brasso(this removes any fine scratches caused by the wool) with a duster & then a final polish with Brasso on a j-cloth that has been moistened. A final rinse with washing up liquid & then polish with kitchen towel