Not much...
since I'd be amazed if you could pull it off twice in one session. It's also cheating, and therefore illegal. There was once a time when I did it a number of times... amazingly without ever getting caught but I don't now because I'm opposed to cheating in all ways now.
If you are captured on tape repeatedly making double-down wagers correctly and then stack it/double it again when asked, I have it on good authority that the tape would hold up against you in court. If you must do it, be advised to do it early in a session before precedence re: the knowledge of how to double correctly is demonstrated.
Spok