How do carb restorers clean the outside of the carb?

"Most" carb remanufacturing companies use "tumble" cleaners on the carb bodies. It is the same process as shot peening. It leaves a very clean surface with a slight texture. I'm not sure any reman companies blast carbs. It's not a good idea as blasting media can get caught up in the carb's passages. I use a 5 gallon container of berryman carb cleaner. it's not what it once was before the gubmint made um weaken it down but it'll still make you have two headed babies.