Have been experimenting with a similar technique which has worked a couple of times, but has not yet worked consistently. Many years ago I used to juggle, and just recently began practicing it again right before going to bed, as I felt that this would be a good exercise to activate the subconscious right before going to bed. On the nights it worked I had a ton of lucids, as my subconscious woke me up about every 30 minutes during my dreams. On the nights it didn't work, my subconscious seemed to not activate as it hardly woke me up at all. Drumming would be another good exercise to try right before going to bed as it also seems to use a different part of the mind than just the conscious.
I usually try to do things with my opposite hand during the day, like eating with the other hand, brushing my teeth with the other hand, etc, as this is how the brain learns and grows new neurons, by learning to do different things that it's not done before. The book I learned this from is called Keep Your Brain Alive, as it explains how the brain learns and grows by doing new things.
Will have to try the writing method as this sounds like it could be a very effective technique.
