I've heard the same thing but haven't tried it. I've also heard that if you keep the lights out for 36 hours before harvest that it increases thc levels. I think the only way you'd know is if you were a chemist and could test it.
I've hear the same thing BK....it just helps them dry quicker. Also, shutting off the light for 24-36 hours refers to going from veg to flowering phases I think. Shutting off the light for 24-36 (I've heard different things) when switching from veg to flower reduces the flowering time and prevents the plants from stretching (plants usually almost double in size during flowering). This is what I've heard at least.