Extended darkness is bs ghetto science.
Witholding water for the last 24-48 hours makes drying easier.
Neither "technique" will miraculously cause extra THC to magically appear.
The less stress and the more normal the plants are treated before harvest, the better.The last thing you want to do after weeks/months of careful, dedicated growing, is to stress the plant in any way right before you harvest them.
Over the last 40 years I have tried just about every urban myth out there and 99% are garbage.
Harvesting healthy, unstressed plants is the only thing I believe in these days.