I use the BPL (Black Powder Lube) that Andy Allwwod makes - about £3 the last 'stick' I bought (for stick think toilet roll sized tube)
Probably last bought one about 2 years agao - it lasts for ages !!!
I chuck about 25 or so minies in a sammich bag with about 1/2 tsp of lube and roll them around (the bag probably still has enough init to do another 25 !!)
Yes they are a little 'sticky' when shooting and you will need a rag with you but hey Black Powder shootin' IS a messy sport !!
Not many times I need to wash my hads BEFORE going to the loo !!! #
Roy