Assuming that you're not planning to restain and remodel the pipes and are merely doing a bit of cosmetic clean up, here's the following that I would suggest:
CAKE: If the cake is thick, use a reamer, like a Pipnet, to trim it back. Do this carefully so as not to gouge the walls of the chamber. Don't bother with alcohol in the chamber at this point.
CLEANING THE AIRWAY: Buy a few shank brushes and a whole lot of pipe cleaners of various types including tapered - bristle and not bristled, fluffies, and regular - bristled and not bristled. Start with the shank brush and a neutral spirit and scrub out the shank airway. Keep rinsing the shank brush in the neutral spirit between scrubbings. Move on to tapered bristle pipe cleaners that have been dipped in a neutral spirit and continue the process. You're done when the pipe cleaner comes out clean.
Next, clean out the mortise. I often fold up a fluffie to make a thicker shape, dip it in alcohol, then twist it into the mortise and let it sit there for 20-30 minutes. That will soften some of the deposits in the mortise.
Follow by scrubbing out the mortise with doubled up tapered bristles and fluffies until the mortise is clean. For tougher deposits in the mortise, use a dental pick, just be careful and patient.
Soak a regular pipe cleaner in alcohol, inset it into the stem airway and leave it for 20-30 minutes to soften deposits. Then scrub the stem airway with regular pipe cleaners until they come out clean. Don't neglect to scrub out the slot in the bit as well.
If, after all of this, the pipe still smells of stale tobacco, or ghosts of tobaccos past, then perform a salt and alcohol treatment. This you can find described online, so no need to repeat it here. If the S&A treatment doesn't work to remove tobacco ghosts then use a boiling alcohol retort treatment. This will pull out any resistant rancid oils from the wood surrounding the airway, as well as the chamber walls.
EXTERIOR: To remove rim build up use either saliva or cold coffee and a rag. Don't sand it. Spit or coffee works fine to dissolve tar and carbon deposits. If you have scorch marks, you might be able to abrade some of it with a coarser micromesh pad, but it's very easy to remove the finish if you're not careful and then you are in the refinishing business.
If you really know how to properly use a buffer, (and I' only met a handful who actually did and many who are delusional about their skills...) then buff away to your heart's content. If you don't own a buffer, buy a jar of both Halcyon and Paragon waxes, which will give you a very nice polish without needing a buffer.
Cleaning the exterior of the stem requires different approaches depending on how badly the stem has oxidized.
If the stem is basically in good shape then a metal polish, like simichrome, will add a nice topping off to the surface.
If the stem is really orange my advice is to have a new one made. But assuming that you are determined to rescue the corpse you can start by soaking it in a diluted solution of Oxyclean for a couple of hours, or longer. If you like pitting your surface, use bleach. Either way, you will still have to remove the damaged material by sanding it off, which is why I don't bother with bleach or oxyclean. I'm gonna have to sand off the oxidized material anyway. You can use a buffer to remove material, assuming that you are one of the very few people on the face of the planet who actually knows how to properly use a buffer, or you can buy a set of Micromesh sanding pads and return your stem to a black glass-like luster. Just work the pads from coarsest to finest and your stem will look like new, and you will get some much needed physical exercise.
Your friend will be thrilled by your thoughtful largess. Or, you can do what I do. Toss the grungy stink bombs in a box, dump them with your friend and let the lazy bum clean them up!
