That is not what the BD looks like. But if there were scenes looking like that, I would simply add some grain.
While this would make the picture look more natural at first glance, it doesn't bring back the image detail that was lost in the DNR process. I know that there are some cases in the trilogy where you added digital grain but I don't really see a real benefit in this. It's just adding something artificial to the image instead of bringing back the original grain and the image details that were removed with it.
I think it's more of a last resort to remove the plastic-looking surfaces caused by DNR, especially in skin. The goal is always to preserve as much of the original detail as possible, but there's only so much you can do when it has been scrubbed and smeared away by DNR.