I love poetry, but think this advice is slightly off. A better way to get un-stuck is free-writing. Just write whatever comes to mind without stopping. If you hesitate, just write "I don't know what to write" - anything to keep writing. If you can sustain this for twenty minutes, you are now immune to writer's block. You know you can always write. This shifts the question to what to write. You find you can sculpt the…
Is there value in free writing? Of course. I've done morning pages. I've also done free writing when struggling with problems in multiple realms (code and prose/novel writing). But sometimes it simply doesn't push you hard enough compared to the forced perception change.
You can certainly TRY to create that change in free writing, but then are you REALLY free writing, since you are limiting what you put on the page?