Shuffling the Illuminati card game

I've recently purchased the Y2K and Bavarian Fire Drill for the Illuminati Card Game. This of course creates a massive draw pile when playing the game. I've started shuffling the deck in sections, swapping around half of each section after shuffling to attempt to get a thorough mix. Does anyone else have any suggestions on how to get a good shuffle with a deck this size prior to playing. I'm hesitant to use an automatic card shuffler as I don't want my cards to potentially get damaged.

Shuffling the Illuminati card game