You can make a dirty iron look like new again with that powerful cleaning duo, vinegar and bicarb soda. Thrifty and Chic blogger Alicia had a seriously encrusted, ruined-looking iron. She accomplished the amazing transformation you see above by "ironing" (with the iron turned off) a paper towel soaked in vinegar and with a little bit of bicarb soda.
Finally, with the steam setting on, the holes in the iron get cleaned out too.
Check out her post for photos and more details on this process.
How to clean an iron with vinegar and baking soda [Thrifty and Chic]