Update on the Turtle Wax ICE polish.....after heating the kettle to as high as 385 deg F and averaging about 350 F for about an hour there was no discoloration or chalking of the polished area, but I can't say it is really noticeably much more shiny than the unpolished area. You can certainly tell where it was polished though; it does look a little different. I checked and water drops don't appear to bead up differently on the polished area after my cooking experiment but I suspect that it probably confers some water repellency when freshly applied, based on how it acts on my truck. That alone might be useful since SWMBO makes the kettles sleep outside when not in use.