I wouldn't.
What's the point? If you know your facts you don't need to memorise anything. The other thing of course is that the questions are not uniform as they are for English, they are different depending on your topics and often use different keywords as well. In MH I've seen explain, account for, assess and some others. The questions could be on anything and often they span across multiple syllabus points anyway.
If writing essays helps you memorise facts and teachs you how to write essays for the key words they use, do it, but don't walk in with a memorised essay and expect to regurgitate it because it's unlikely it'll work.