..................And if they still turn out dull and dirty looking, paint them with a small brush (child's paintbrush from a watercolour set) and a little silver or matt black aerosol spray paint squirted into the cap of the can and painted on quickly while it's still runny. I do this a lot on small parts for MTB's I flip - Oxalic acid bath in a basin, rub with fine wire wool and if they don't come out bright and clean, a splash of paint. The detail makes the difference, the bikes look newer, a lot cleaner and tidier.