I’ve tried this tonight using the free iPhone app, called ‘Smile Alarm’. It’s an alarm that can play your MP3 collection as alarm sound, but in order to make it stop, you have to solve a number of puzzles, calculations and/or games. It’s intended to force you to wake up and get out of bed, but I’ve used it re-activate my logical part of my brain at 6:00AM and then going back to sleep. 1,5 hours later I did have a LD, which was the first in 2 weeks or so. (Only downside was that I had configured it incorrectly, forcing me to solve so many puzzles/calculations, that I had a hard time falling back to sleep).
BTW, it’s not my first time that I’ve had a lucid dream after having to solve a logical problem half way during the night, so for me it seems to work. It makes sense that getting your logical part of your brain to wake up with a puzzle/math is like doing a WBTB, but without having to get out of bed.
By the way, the idea itself to use math to kick-start your brain and get lucid isn’t new, though:
https://community.ld4all.com/t/new-ld-technique-called-wmbtb-discovred-by-alex-curtis/34957
https://community.ld4all.com/t/the-secret-to-having-lds-every-night/33678
Edited into previous post 