I’ve used this technique (freewriting) on and off for many years. Of late I have fallen out of the practice. It used to be part of my morning pages (MPs) practice which I abandoned about two years ago.
I sorely miss both morning pages and freewriting. I have rediscovered freewriting through an excellent book Accidental Genius by Mark Levy. This has set me on a sound footing to reestablish both MPs and freewriting.