This is among the three or so most-asked questions on posts, so I feel like I'm repeating myself too much, but since you ask ... first, I scoop the bowl empty usually with a pipe nail. Then I wipe out the bowl with a paper napkin or towel; I'm one of those who doesn't build cake, just maintain a thin carbon layer, and then don't have to ream. Then I run a pipe cleaner through the pipe, and usually one is plenty. Then I polish up the pipe with a dry bandana or polishing cloth. I'd avoid adding wax, polish, grease or anything else on a regular basis. This just prompts residue and after a while will cause the pipe to look less rather than more bright. A little wax or something on an annual basis for a heavily used pipe might work, but I'd recommend against anything on a bowl-by-bowl basis. More elbow grease, less other stuff, product or whatever.