I sure hope either one of those will work. I suspect that it would take more force to expel a brass jag and patch, that has been pounded down dry, then a lead ball which has some give to it. Might not be so easy peasy. However, yeah I'd say the next step for sure.
What is this "peanut oil". Are we talking literally peanut oil? When I used to 1/4 mile race, I'd hear guys talking about putting peanut oil in their fuel, but never understood if that was slang for something else, or actual peanut oil.
If it is, that is pretty thick oil, not sure if it would have much penetrating properties. ?? Just a thought, but I'd flush that bore out with kerosene, or something like that, alcohol, gas, or what ever, (don't light up a cigar) and then put some serious penetrating oil down the bore to soak. I think even WD40 would be better, or liquid wrench. Or something other than "peanut oil" or Rem oil. Probably some other products out there more suitable to your "situation". Then I'd try to grease or blow it out.
Don't feel too bad. I have a replica 1861 Springfield, and when I first got it, got to looking at the tulip shaped tip of the ram-rod, and got to thinking: "that would work as a jag". So I tried it, seemed to work great. Then I tried it in a fouled bore. No kidding, I was pretty sure the barrel would have to be un-breeched. I mean, it was STUCK, and no "give" to a steel "jag" and a steel bore. But, it finally came free after some soaking, (but clamped in the bench vise will all my weight and strength pulling on the rifle) but I sure thought I'd bought the farm for a couple of days.
Well Darth, good luck, hope you get that out soon. One steep learning curve, aye?