Smith + Nobel White Granite Plus

Very happy with the non stick inside of this pan. We bought two different sizes. I like to make pancakes and they're perfect and just slide out of the pan. However, the lovely white outside edges at the base of the pan and also the stainless steel base have stained badly. I started off washing by hand, but now I've given up because there doesn't seem to be any point in being careful. The stains don't come off. I cook on a ceramic hotplate.