Sandblasting is probably easiest and safest, though it does require practice and equipment.. an air compressor and the media (sand). A blast cabinet helps a lot as it recycles the media, which can be expensive. Media for frosting glass is usually aluminum oxide or silicon carbide, which comes in different grits or bead sizes. Something finer than 150 grit would probably be a good starting point.
Maybe some glass shops, glaziers or other glass craftworkers would have the setup to do this if it sounds like a bit much. Glass can also be chemically etched, but might not be a viable option for doing just the inside surface of a cylinder. With sandblasting you can use masking tape (and paper stencils) to frost specific areas of the glass.
