I use this unexpensive tip (steel wool + WD40 spray) to remove some plastic from rain cloth melted on exhaust. It worked perfectly with chrome exhaust without leaving any mark. If you are afraid, remove one of the cover of the exhaust and try on the surface which is not visible.
Purple Metal Polish is a no-rub metal polish which gives a high quality shine on metal, chrome, aluminum, brass, and plastic with very little effort. No questions asked, money-back guarantee!