I've never done the Disney / Universal 6-pack, but I've done the Disney Domestic 6-pack.
Went to EMH at DHS for TSMM, followed by rides on BTMRR and HM at MK. Went over to Epcot for Soarin' and a snack, then to DAK for the first show of FoLK (sorry ... not a fan of EE).
Then, I drove to OIA and got on a non-stop to LA. Due to to the time zone thing, was able to get to
Disneyland by early afternoon. Rode Big Thunder and Haunted Mansion at DisneyLAND, saw their parade, then went to DCA for rides on their Soarin' and TSMM, capping off the night with a stroll through DTD Anaheim.
It's the time zones that make that one work, though. You couldn't do it if you started at Disneyland and then went to Disney World.