Once you have used whatever method you chose to get your stem nice and shiny, to maintain that shine (and to limit further dulling) I would strongly suggest wiping the stem over with baby oil (Johnson & Johnson). It works just as well as obsidian oil and is a heck of a lot cheaper. Just apply with a finger then wipe off with a rag or tissue...job done!
Initially I bought a small tube of pipe stem polish (think it was Dunhill), but when I learned more and got more into the hobby, i found carnuba wax to do the best job - although this is after many smokes. I don't tend to polish after each smoke.
++ 1 on the unflavored Chap Stick after each smoke. It contains an antioxidant which will, obviously, prevent the stem from oxidizing for those Vulcanite stems, plus it's intended use is for the lips. Also, it's easy to use, easy to carry, and it's better than messing about with some liquid. Just a very small dab on the stem and then simply rub it about.
I store my pipes in a temperature controlled subfloor vault located twelve feet beneath my home and I only smoke in dark, sterile, vented rooms. This keeps my vulcanite in tip-top shape... at least I assume it does... because it's too dark to really tell.
"...because it's too dark to really tell."
No Nate, it's not too dark at all, it's a direct result of all that stem polishing you did in your youth :rofl:
You should have listened to your Mother!