so sorry this happened to you. I learned a long time ago that eventually all irons will do this. I don't care if it is a top of the line Rowenta or an economical Black and Decker or Shark, eventually it will leak or spit. I don't use water in my irons any more and haven't for going on 20 years. I keep a spray bottle of water at my ironing station for when I need a bit moisture. I find my irons last much longer and I never have to worry about this happening.
As far as removing the stains, as Judes suggested I would dunk those blocks in plain water to try and get the stains out before they have a chance to dry out and set. If they are rust, Carbona makes a rust remover product. I have seen it at Walmart but I have never tried using it.