There are a number of prank gift boxes available on Amazon. These would make entertaining packaging for whatever you decide to bring to the white elephant party. The boxes are empty and are intended to be filled with an unrelated gift.
If people believe that the box actually contains the pictured product, it may remain unopened for some of the gift exchange. This will crete a second surprise when the box is finally unpacked. You could hide a desirable gift inside, which would normally be stolen during the course of the game.