[MikeK]

I can offer another suggestion to make the media (grit!) flow better through any siphon gun. I worked one summer while in school at a repair shop that had several blast cabinets and also blasters on wheels. They were all modified with the addition of a bin vibrator- some were 110V, some pneumatic. They were bolted on the side of the bin a few inches above the siphon pickup, and the siphon hose was clamped to the bin right next to the vibrator. Very noisy when you stepped on the pedal, but no clogs with the media 'fluidized' by the vibes.