I just read today that sprinkling some salt on the ironing board and moving the iron back and forward on the board cleans the plate. (I don't think you turn the iron on, it didn't say anything about it)
That sounds like a really good one.

I have used al foil before, my mum does that. Also have done the non scratch scour thing.

I bought a stick called: Vilene iron cleaner. You rub it on when the iron is hot and it stinks to high heaven and is kinda messy. I am not really sure if i am recommending it or not. I am just telling you and you can make up your own mind. The fumes smells pretty bad. I bought it from a textiles wholesaler in Sydney. I don't know if I did it right because it didn't work brilliantly. What a great wrap I've given it!