No, I do not believe in this "ghetto science".
Extended darkness just causes a plants' metabolism to almost stop, and a plant with an almost stopped metabolism can not support healthy trichomes or prevent the break down of THC.
Why anybody would want to stress their plants right before harvest and after weeks/months of careful cultivation is beyond my comprehension!
Harvest a happy, healthy and unstressed plant after a normal routine of normal sleep and your buds will be at their peak and forget about the "extended darkness technique" BS would be my advice.
This whole myth about extended darkness came from one study whereby one plant showed a miniscule increase in THC levels (and all the others a decrease) and was not repeatable or 100% effective in 100% of all cases.
However, "bro science" picked up on this one anomaly and through the magic of the internet, a new "technique" was born.
The fact that it does not work doesn't seem to matter, people just follow it blindly without ever questioning it.
As they say......."why let the truth get in the way of a good story?".