I don't know how helpful you'll find this but its kind of a condensation of my decent (ascent?) into B/P shooting. I probably made every newbie mistake humanly possible & went from curiosity, to experimentation, & from ultra traditional to fairly modem techniques and materials in the process.
I went from an ultra-conservative PC/HC forum to a wild & wooly one passing through several as I went. Each had something to offer, but I found my perfect level of involvement by taking a little from each & dong a mix 'n match as I went, taking the good & dropping the unsuitable.
I found most traditional methods, frankly lacking, but did find more modern equivalents that worked better. Some techniques were better traditional than modern equivalents & some made for an interesting combination of ancient & modern! Lubes would be one of those cases.
I tried goose grease, sweet oil, moose milk (& other unmentionable "moose-derived products"
) , "Bar fat", rendered animal fats & so on for grease too, & found the period lubes were in need of far more maintenance, & far more trouble-prone, than modern equivalents, but a mix of modern synthetic oils (pick your favorite, they all seem to work as well) or gun lubes and a cleaning the bore & chambers with regular ol' alcohol prior to use gave me the best of both worlds. What I do now is store & lube with a good synthetic oil, gun or automobile both seem equally functional. Right before shooting I swab the oils away from surfaces with direct contact with burning powder only, & then use a patch to put a thin layer of the grease into those now de-lubed areas. After use I clean wit hot soapy water & a water rinse, dry thoroughly with heat & air, & then reapply modern synthetic lubes for the next storage.
I did stick to a period-style grease, 40-60 mix of Crisco & beeswax, ( as it seems to work well with the 1858's cylinder pin, but this is about the only PC item I use.