More to explore:
▶ Art Glass Grinding Wheel Demonstration - YouTube
Accurate Grinding Glass
grinding glass with a wet angle grinder
Glass Grinding & Polishing Tools: the process of cutting wine or beer bottles is simple enough, but the tutorials all seem to be lacking in the smoothing/polishing process part.
grinding glass with a wet angle grinder and my glass bin
This bureau pitcher with glass is hand blown from recycled glass and etched on a grinding stone.