A similar recipie has been out there for a while, my mother used to use it to polish brass around the house, her recipie (for smaller batches) was 1/2 cup of white vinager to a table spoon of salt, then she mixed in white flour make it into a paste, or she boiled it and dropped smaller items in to cook them clean (boiling worked GREAT on greasey/dirty stuff BTW). I'm not sure if the Lemon juice (citric acid) would add much strength to it or not since vinager is a pretty acidic allready but it couldn't hurt.
