Google vapor honing or vapor blasting. You can send parts out for service or may find someone local. Probably the best way to clean a carb but it isn't free.
When I started working for Douglas Aircraft Company way back in 1984, we had a HydroHone blast cabinet that used pressurized water and a variety of abrasives. One of the things that I discovered while using and experimenting with it was that I could use just plain pressurized water and remove paint from the primer. Another thing that I could do was to change the pressure setting and give the oxidized paint coat a “water polish” surface finish.
