Is there a way to check broken links internally?

I had the stupid idea that if I changed the slug of a post, the change would propagate through the database and automatically change links referring to those posts. OK, dumb, but done. I now need to recover a bunch of broken links. Worse, many of the posts are in edit, and are privately published. The Broken link checker plugin marks all the links in the private posts as broken, because they look 404 not found from the outside. So its output is a mess and no use to me.

I therefore wonder – hope, desire, long for – if there is any way to automatically check links internally, by searching the database?

Many thanks