Dritz has a good iron cleaner. It comes in a tube like toothpaste. Squeeze about an inch on an old towel and rub your hot iron over it. The gunk comes off easily this way. Just keep rubbing the iron over clean places on the towel until there is no more residue. The iron needs to be as hot as possible for this to work. There will be some fumes, but it is not an offensive odor. Works for me. You can get this at JoAnn's when they have their half off notions wall. I think Walmart has it too.