We know that according paranormal scenarios, after people die victims of a tragic dead, their spirit stays on earth trying to get justice or revenge or finish things, so what if we blend that idea with some of The Walking Dead zombies, we get a very creative solution.
Recipe to kill all zombies on earth according to Supernatural:
First we have lots of main characters stupid but mostly tragic deads, for example, we have Dale's dead, Shane's dead, Hershel's dead, Lori's, Merle's, etc... Now we have to call them with a Ouija board, then we have to tell our beloved dead people to go and kill some zombies to get some payback.
And finally we wait and problem solve, we have millions of evil spirits killing zombies for us. Or at least that's what Supernatural has taught me through years.
Thanks for reading this shit, I'm a little odd today. lolz