I don't know what others use but I clean my metal with purple metal polish. Always leaves a slight grey hue. Residual polish I guess. Well I used a product called Bowdens Own Fully Slick today . I use it on my car normally. I took a few goes to get the metal polish residue out but it has left it super shiny, slick to touch and repels liquids. I recommend you all to give it a go. I also clean my phone and glasses with it