Yeah the whole 3-4 weeks thing is exagerated. Unless you smoke really heavy, you should be good within a week. I hear about Niocin (sp?) that's supposed to clean your system but not sure if it works. The homie bought some fake piss for a job interview once and he said it worked. He stashed in his draws and when they told him to piss he poured it in the cup on the low.
Fake piss is the answer. NEVER use your own piss if you might be dirty, You will get away every time too unless they monitoring you like the military or probation officers. Some places will be like leave the door open, but just hit they ass with the

They can't make you piss with the door open, and even if they do, they can' look at you while you doing it, as opposed to bytch as p.o.'s who be looking at a nikka dikk like
All you need to do is obtain the clean piss and put it in some type of small leak proof container. Next, put the piss in your nutsack. Wear tighty whitey's so the bottle won't move around or fall out. The piss will NEVER drop below body temperature this way. This is important because most of those dip strip test have a temperature reading that needs to be in a certain range too. If you get the piss earlier then the test is, you can always heat it back up. Once you put it in your nutsack, the temp will drop down to body temp.
This method is 100% foolproof, tested and proven for years. My whole circle of friends and acquaintances has been using this method for 7 or 8 years now, and nobody has failed a piss test yet