It's also called vapor blasting.
I can see a way of doing it, large coolant pump pumping bead/water slurry and an air line into the nozzle so you can give it a blast. I would have given it a go but I needed a water tight cabinet.
I had a try with a 50CC of bead in a litre of water in a Schutz gun, amazingly it worked, bit messy and it took a few litres but I blasted the rocker cover from my bike. Image is the spring covers, don't need to say which one I blasted.
Used to use one at work ,huge advantage is no airbourne dust ,media is held in suspension in the liquid(water) by air jets and possibly by a return from the fluid pump,mixed at the gun with air as well,worked very well....OR you can purchase a kit now to go with pressure washers and it sucks sand/media and mixes in a special lance,i've not used one but it should work as long as the lance and parts don't wear to quickly...