Hi caroline, yes i used a lint free cotton cloth to rub them back a bit. Also tried a brass brush, a pro polishing pad and some jute/sack ribbon which also works well to remove the rainbow effect somewhat. It would be a lot easier not to have the rainbow in the first place though (as i either have to dip more or rub back a lot, some of my items are still a bit unpleasantly red looking after my efforts) i thought maybe i should try platinol diluted with distilled water and see if that helps any. Also wondered whether the temperature of the metal or water might be affecting things? I should try neat platinol too, i just felt that the copper would go very dark and peel off. But who knows