I've also heard of those methods and I have increased the dark hour to 14 for the last few weeks. The theory behind the total darkness is, supposedly that is when resin production increases. The amount of resin produced by a plant is all based on genetics so if your doing everything properly to maximize the plants genetic potential, and that may include the darkness theory, then in my opinion it would be all for not. The amount increase would be so little it wouldn't matter unless you're looking to cut electrical costs. I haven't found much evidence proving that, probably because it hasn't been researched yet. Until cannabis is more widely accepted among the medical/political majority, I suspect that little research will be done on all aspects of the plant