If you're going to put the tubes in a zip lock bag, get some small desicant (moisture absorbent) packs to put in the baggie - not the tube.  The ones about the size of the sugar packages on the table in restaurants, etc.  I guess it's just me but I don't use mineral oil for storage.  Rather, I use gun oil, i.e., Remington Rem Oil.  Machine oil is good too.  I sometimes use Food Safe Mineral Oil to lube the joints.  Further, once prepared for storage, I don't go back and repackage unless I have a reason to get to the knife.  Otherwise, I just leave em in the tube undisturbed.