I have an 1892 in 44-40, I have completely broken it down for cleaning and just wiped the action and bore swabbed. It was virtually clean inside when I did the tear down cleaning. I have only used BP cartridges in it. The 44 WCF cartridge really does make for a clean firing rifle.
Edited to say also....
Very nice rifle Capt'n. I'm jealous, I would happily fire BP cartridges and tear that rifle down every time I fired it.