Could I take chunks of meat or fish and preserve them by putting them in a jar and covering them with mineral oil? It would create an airlock and keep it preserved and able to be kept at room temperature.

Salt for the fish, layered, after chunking it up.
Red meat in oil? I don't think your airlock will help much when it gets warm/hot. Now, if ya kept it in a fridge, that might be a different story.
SB is probably cheaper than the oil anyway, to preserve the red meat. Unless you get that oil free.

Thanks! I was just curious about it since some old bait recipes call for it as a base.