I haven't had success with WILD before bed, or even afternoons.
( I never experience the stereotypical sleep paralysis stages,and can relate to the 40-50 minutes on the clock...)
But I think you're wasting your time on the wild @ night, because you could easily use those same 40-50 minutes to actually fall asleep.
Set an alarm, and then try the WBTB. If you're going to spend this much time to LD, why not experience one ?