The 30-30 was never a blackpowder cartridge and I don't think the advice applies. 45-70, 40-65, 38-55 or 44-40 can appropriately be loaded with the fill-it-up method. These are straight-wall or lightly necked (44-40) cases. I know some folks have loaded the 30-30 with BP, but I don't know what load they used. The stuck case could have been excess pressure or dirt related to the BP.
Remember the BP is corrosive and you'll need to really clean up afterwards to prevent barrel damage.
Ed