I believe that the "vapor blasting" still uses an abrasive media, but with a slurry. You still have the issue of abrasive media getting into places that may be difficult for it to get out of, even if the wet slurry blasting produces a finer finish. Abrasive media will do some surface alteration. Ditto for glass beading, the glass is simply another kind of abrasive.
If some kind of blasting is what you want, I'd vote for dry ice blasting which I understand is highly controllable but more importantly doesn't leave ANYTHING behind.
If you don't want to alter the surface but just clean and brighten, chemical cleaning is the way to go.
