Would this work? You start off in a double battle with Shedinja and Gengar (or some other Pokemon with Skill Swap), and Gengar (or whatever it is) uses skill swap on Shedinja, Then Shedinja switches out with Sableye, and Gengar (or whatever) uses Skill Swap on Sableye.
Trying to skill swap Wonder guard is not possible. It can be traced however. they blocked it out so you can't skill swap wonderguard in generation IV.
In the latest versions of pokemon Wonder Guard cannot be an ability of any other pokemon except Shedinja.
It cannot be transfered to another pokemon by any means - unless you cheat.