Folk technique, formalised in the 1980s
WBTB
Wake Back To Bed.
How to run it
Set an alarm for 4.5 to 6 hours after falling asleep, stay awake 15 to 30 minutes, then return to bed applying MILD. The calculator on this page works out the clock times for you.
This one depends on waking at the right point in the night, and “about five hours” is not precise enough to act on. Work out your own alarm times from your bedtime — the calculator uses the 90-minute cycle so you wake between cycles rather than out of REM.
What the evidence says
Rarely used alone — it raises the odds of whatever else you are doing, because it lands you in the REM-dense final third of the night. Aspy (2017) treats it as a component rather than a standalone method.
Context for that number: only 23% of people have a lucid dream in a given month at all, and 55% have ever had one. So a technique landing anywhere in double digits per night is doing something real — and is still not the switch these methods are usually sold as.