So you mean just sleep until you wake up in the morning, then go back to sleep? If so, I do this quite often with much success. But I'll only have a few dreams this way before being too awake to go back to sleep.
Just make sure you've had a lot of vivid dreams that you've recalled before attempting this, otherwise you might end up just wasting half of your day sleeping with nothing to show for it.
You mean you need to have recalled dreams earlier in the night/morning? But wouldn't you be guaranteed to have had
REM during the night, remembered or not, if you've already slept 8 hours? Why would it matter if you have recall at that point?