Morning pages, dump pages, purge pages... they are all the same thing. You write and write until you get all the *crap* out of your head. There is a book called, "Write it Down, Make it Happen". It's about a book that has to do with writing. Writing lists, gratitude, notes, dump pages and more.
One of the best (in my opinion) exercises in there is about dump pages. It's when you sit down and commit to either 30 minutes, or 3 full pages of writing. It doesn't matter what