For me the answer is, "It depends."
If it's in the brown to green category and there's no nomenclature on the stem, or none you want to preserve, 30-minutes in straight bleach (which kinda furs up vulcanite) then rinse with water and wet sand with MicroMesh fabric 4,000 through 12,000 for a glasslike finish.
If lightly oxidized then a soak in water with a tablespoon or two of OxyClean, rinnse and sand as needed.
If just a bit discolored it's pretty easy to wet sand a MicroMesh sequence from 6,000 to 12,000
If nomenclature is in-situ and you want to preserve it, same as above but cover the nomenclature with a glop of Vaseline before soaking and beware sanding or oversanding inked-on details.
Nothing wrong with a low speed buffer if you have one, cotton wheels and proper use of an emery, tripoli and white diamond sequence but lower speeds are important - you can overheat and mess up some vulcanite in a heartbeat.
IMO.
