I started using spray starch a few years ago and always tried to remember to clean my iron and sometimes I would forget. And since I was ironing shirts for my DH to wear to work I could not have the marks it could leave. So somewhere on this board someone wrote that they use the Mr. Clean Magic eraser on the cold iron and it worked well. Gave it a try and sure enough it worked. But someone else wrote they kept the "used" dryer sheets and ever so often while ironing they would run the iron over the dry sheet kept on the ironing board. I started doing that and have not need to use the Magic eraser since. I just leave it on the end of my ironing board and spray it with a bit of water and run the hot iron over it. Mr friend thought I was crazy but it cleaned up her iron quite a bit too.
I tried it out of desperation because I needed to iron a shirt and didn't have any iron cleaner. The salt and brown bag did not work for me but the Magic Eraser worked. Not as much as I had hoped though so bought a new iron and kept it clean since. I was worried the heat of the iron would melt the dryer sheet but it didn't. The Magic Eraser is on a cold iron.