Kerr Black Holes for Time Travel?

First off I don't believe in time travel, I just want to know why other people think that these black holes may be our key to it. From what I understand, the singularity of a Kerr black hole is a ring like a doughnut instead of just a point. Some people think that traveling through the middle of this ring will transport you to another dimension. My question is why would it take you to another dimension instead of just pulling you back to the singularity. To me, it sounds like you would just pass through the ring. I don't get why anything special might happen.