sask3500: I've known some bp revolver shooters to completely fill the all the interior space of the action, with synthetic grease. To eliminate bp residue from entering the action and possibly causing corrosion of interior parts. I haven't done that....though it seems logical, as the gun doesn't need to be stripped very often, but... I am not sold on the idea. The hard truth with bp guns is that, in my experience, stripping them is the only really reliable way of getting them clean and keeping them corrosion free.
The problem with the 1889 is its fairly complex lock work. Which could make a full disassemble risky, unless thoroughly familiar with how these guns work.
If okay with stripping your 1889 down completely: As far as simple but good, basic bp cleaners goes....ordinary hot, soapy water is hard to beat. Works exceptionally well, at the job. Followed by rinsing in very hot water(Metal should be almost too hot to handle). The heat speeds up the drying process...especially in those nooks and crannys that might be hard to thoroughly get to, with a q-tip, patch or paper towel, etc. The hand slot, being a regular culprit.
Also in line for bp revolver cleaning/lubrication, two alternate products come to mind: Ballistol. Non-petroleum based, so compatible with black powder. Works well full strength, as a lubricant and protectorant. When diluted, does double duty as a cleaner and lubricant. I like an 8:1 or even 9:1 mix ratio. The ratio of oil to water doesn't seem too critical. When the water evaporates, a thin film of oil is left behind on metal surfaces. Good stuff. Of course, there are many other equally good gun oils. This is a personal choice.
My all time favourite bp cleaner, is ordinary: isopropyl (rubbing) alcohol. Removes sooty residue in a jiffy, leaving metal parts squeaky clean. Have used it exclusively for cleaning up bp residue, for many years. Works well. I like to use alcohol to swab off the cylinder face after several rounds of shooting. Also the bore and chambers. Plus any other surfaces where residue may accumulate. Followed by light lubrication, where needed. A necessity with alcohol, as it cleans the surface very thoroughly. When/where it isn't possible to fully disassemble a gun...this is my go-to cleaner.
One caution with Pyrodex: This bp sub is highly corrosive and should be cleaned off metal surfaces as soon as possible after shooting....within reason....to prevent flash rusting. Rust can and will set up very quickly if left unattended for any length of time.
Ordinary bp is corrosive too, but not quite so bad. Though still needing attention. Another powder which is also highly corrosive....especially to brass cases, is APP. Cases should be dunked into a container filled with water(neutralizes the acid), as soon as possible after firing. 777 is not as bad as bp or Pyrodex. But ,I follow the same procedure with this powder, too.
Note: Many shooters dunk all their cases into water right after firing, regardless of powder type. But, I've found that with Goex or Swiss black powder....in some instances, this process can wait until a person gets home. A personal choice, only. If you wish to dunk 'em...by all means. Some shooters will have a container filled with soapy water with them at the range firing line, or close to their loading station. Plain water neutralizes the acids, just as well.
Cleaning bp guns seems like a lot of work. But really isn't. Once you get the process down.
Hope this answers some of your questions.
Al
ps: I will be away all next week. If a question comes up, will try to answer as soon as possible.
