WBTB by itself works best if you stay awake long enough so when you finally go back to bed you hit REM right away due to the rebound effect. This of course is easier said than done, not mention the risk of unable to fall back to sleep. IMO it is okay to try this long WBTB + WILD combo once in a while but in a long run you are better off with shorter WBTB combined with non-WILD techniques such as MILD and SSILD.