I think using BJJ and playing around in the guard in a rematch is the wrong game plan to have. I think the fight would even go a lot worse if he came into the rematch with that mindset. The Big Foot is a respectable BJJ black belt and he got absolutely schooled (and even that's an understatement) on the ground trying to mess around in the guard.
Unless your names Werdum, Big Nog or Mir, trying to control Cain on the ground and work for sweeps and subs is a bad idea.
His best bet is to do what he did last time - get up as quickly as possible, but this time actually punish Cain for missed take downs and actually develop some kind of offensive clinch game with knees, elbows and kicks.