Paasche air eraser is a mini sandblaster good for small projects like glassware. You could probably find a cheaper equivalent through Harbor Freight.
Paasche has their own little compressor or you can use an inexpensive pancake type compressor.
Aluminum oxide is real nice on glass, leaves a nice fine finish.
You want either a cabinet or a face shield too though, 'cause you’ll get blasted in the face by the abrasive bouncing off the surface.