Maybe I am cleaning them improperly or doing something wrong, but my baking sheets form a corrosive metallic film over them when I wash them. When I dry them with a towel, the towel is gray from the nasty residue. These are allegedly high quality aluminum baking pans. When I bake on them, I just try to wipe them well and then line the pans with foil or parchment. Just seems that the pans should not be covered in this stuff. I am thinking I just need to buy stainless steel pans to avoid this problem. Has anyone has this experience and have you used solid stainless steel pans? Any thoughts on this problem and if stainless steel is better?