what about this........GENTLY........i repeat GENTLY get a drywall screw 1' 5/8" long preferably, screw it into the bullet, slowly so not to create heat, providing its a soft bullet, use the screw to extract the bullet out of the cartridge case i.e. claw hammer/pliers, after u get the bullet dump the powder out, then u just have the primer to deal with, come from the other side set it off.. i.e. nail/punch, with a good pair of welding gloves on and eye protection.....then get as ruff as need be to get the case out........ I didnt get the call sign Redneck Messiah for nuthin
I think that is a pretty good idea.
If that doesn't work right away I would say take the same concept a step further and drill a hole very slowly through the bullet. You could start with a small pilot size hole and graduate in bit size until the powder will pour out. Drill very slowly and with a new sharp bit. Wear protective everything.
I might add that I would make sure that the bullet is very soft lead and very unlikely to spark. Also, this should probably be tried after the oil soaking to see if that worked first.