I don't think the super Idol is in play anymore. I think that he's going with that plan to get to final three by making people believe that he can still use it at 4. If he really thought he could use it at 4 he wouldn't have acted like the plan involved some kind of deception.
This is the guy that built not one, but two "spy shacks." No scheme is too whacky for Tony. Knowing his luck, it will probably work.
I agree, I think both idols are done but he wants the others to think the special idol is still able to be played (as only he knows the rules on that one) so they don't try to vote him out next time if he doesn't have immunity.