We already know how it would work. Shedinja would simply be unable to be killed by an attack. It can be done in triple battles. There's some video other there of a Blissey using Skill Swap with Skarmory and then Golduck using Worry Seed on Shedinja and then Blissey using Skill Swap again on Shedinja.
My NIDOKING brings all the boys to the yard: http://goo.gl/ExAoe