As snother audio person, I will add that unless you actually enjoy the trial-and-error process, your time might be better spent trying to locate un-mixed soundbites. The M-S processor concept seems to be a more advanced version of the phase cancellation techniques mentioned above (albeit with more fine control over the phase of the signals).
If you DO want to work on it - go, man, go! You will definitely learn what works best, what you can live with and what you can't.
Having never listened to the isolated center channel of the DTS Master Audio from the Blu-Ray - can someone verify that the music is present?