While I salute NORML's efforts in their drive towards MJ legalization, their info on drug testing leaves alot to be desired. They need to just stick with their drive towards legalization.

Cleanout "timetables" should never be relied upon because they are almost always off the mark. They never take into account the so many variables that affect THC-unloading. For any scientific study/experiment to have any validity, you can only change one variable. Multiple variables are useless from a validity standpoint.
The only effective and accurate way to gauge cleanout times is periodic testing with a THC test kit.