I am as OCD as they come. That being said I take perverse pleasure in letting my pipes get a dirty as possible. I like watching the cake build up. I never wipe out the bowl. And I only run a pipe cleaner through the stem when it starts leaking.
I like to build up the grime for as long as I can. This is partly out of necessity because I don't like to waste any time with day-to-day upkeep. I smoke the same pipe day after day. It rests at night and through most of the day. I really only have one to four bowls of shag per day. Of course there are also days, even stretches of days when I don't have the time for even a 30 minute smoke.
After a certain point I decide that it's time to reset and I will do a highly obsessive deep clean of my pipe. I totally remove all cake leaving bare briar. Paper towel, Q-tips, pipe cleaners, bristled pipe cleaners, fluffy pipe cleaners, and distilled water. Also, isopropyl alcohol for the stem.
I am interested in using alcohol on the briar, but I have not yet determined if this is a good idea. I read a post explaining that the alcohol removes some component of the briar and might thereby weaken it over time. I would like to use alcohol on the briar to sanitize it and remove tars and oils, but I am not ready to try it yet.
I fill a small condiment dish with distilled water. I dip Q-tips into the water and then use the moist Q-tip to both moisten the cake and remove it. I alternate between Q-tips and the dull reamer on my pipe tool. Wet Q-tips and pipe cleaners for the stem and shank too. Bits of rolled up paper towel are great for cleaning the shank.
I would run the pipe under under the faucet, but the water here is so heavily chlorinated that I can't even drink the stuff. So I don't want that stuff in my pipe.