I have really been trying to like fleece covers and AIOS. They are so soft and seem like they would be so comfy and cozy. But everytime I have put DS in a fleece outer it has leaked. And I don't leave him in long - just one little pee and the cover is all wet and soaking through. Is this just the way fleece works - and if so, why do people like it on the outside of diapers?