I just bought one of these:
NorthStar High-Pressure Abrasive Blasting Kit Handles up to 3500 PSI | Air Accessory + Tool Kits | Northern Tool + Equipment
But haven't used it yet. I need to clean up a couple of rusty steel door frames in a concrete block building. I don't have a large air compressor, but have a pressure washer, so this looked like a good solution. I was also concerned about the mess from air sandblasting. I'm hoping that the sand will stay fairly close to what I'm blasting.