> I'd be slightly more confident (slightly) that editing the post might cause the core data in the db to be updated, however.

FWIW, I believe this is still true of reddit. Deleting a post doesn't actually delete it. It just no longer shows on the webpage. To really remove it from the database, you need to edit the post/comment, replace the contents with something simple (e.g., the character "a"), save it, then delete it.