This was Arm & Hammer baking soda so I don't think it was anthing special. They were able to blast the paint off pop cans without removing any metal.
This same technique is used by dentists for cleaning your teeth.
Their machine uses a 2 jet nozzle, 1 for baking soda (Arm &
Hammer) & 1 for water. My dentist said it used about 35# air
pressure. His was pretty pricey, $2000.00. I’ll bet we could do
it for less. How about the air earaser?