How do carb restorers clean the outside of the carb?

If you blast it, you ruin it, as far as I'm concerned. The surface finish can't be duplicated once blasted. It's a little bit shiny, and a little bit porous. That disgusting looking, chlorinated stuff that stings your eyes a bit, and has an oil floating on top to prevent it from evaporating is the stuff. It will dissolve anything on the carb. If it's corroded, well then you're screwed. That metal can't be put back, but blasting will surely ruin the appearance, plus I don't know how one can guarantee they get all that media out of all the passages.