Nice attempt! I was hoping for some success from my side as well but unfortunately things didn't go as planned. I woke up after 6 hours of sleep exactly, naturally, went to the toilet, took some vitamin-B supplement, and tried this technique. However, I fell asleep within 10 seconds from starting the imagination. 2 hours later I woke up again, remembering some quite detailed dreams but nothing about lucidity or w/e. I decided to try again but I just couldn't focus, my thoughts would take over every time after 5 seconds or something. I couldn't even get back to sleep so I just got up.