There was some research lab that tested this awhile back but they have since broken up. They claimed that up to 48 hours of darkness before harvest could increase trichome production but mostly just with 'white' strains.
I believe this one, but I think that unless you know what strains it really works with it isn't exactly worth the effort. In theory if a plant is making babies and thinks its sun will never come back its going to do everything it can to make one last attempt to better itself before it dies. Putting your plants through this shouldn't really hurt anything, although you may want to think twice about harvesting a plant that has gone without water for an abnormally long period of time because then the buds might dry too quickly (and that is a bad thing).