What really works is to stop using it !
Niacin alone does not work...trust me i've done months worth of experiments to try and find a working system. Ok basically what niacin is is a diet pill, it burns fat without you really doing anything. This is good because THC is fat soluable so it stays in your fat. So you take the Niacin, (i've found that 1500mg is a good dose for me at a time. Really anything over 1000mg can hurt you but thats if you already have a weak liver, don't try to overdo it is all) become red and blotchy like youre infected with some resident evil virus or something, this should only last for about 45minutes by the way and it is accompanied by being really really hot. It's normal and harmless, your blood vessels are dilating so your body can cool down via carrying blood to the surface. Now with all that fat you just burned taking the pill you've essentially smoked some of the THC out of your fat and into your blood, where it goes next is to be filtered out in your liver and kidneys. Here it will stay untill you pee it out...this is where water comes in. Youre going to drink it...a lot...you want about 1 liter per 20lbs an hour, this will make you piss like a pregnant women, ergo expelling the THC quicker through urination. But were not done, water and niacin isn't the only 2 things to the equation. The THC is also expelled through sweat, and for those of you who are reading this and thinking ahead....yes..thats right....you will have to exercise. Jogging for 30mins a day did it for me, not only does it burn more fat, (smoke out that THC) but it makes you sweat so its pretty much a double K.O. So let me recap, niacin(around 1500mg perday), water (1 liter per 20lbs an hour, EVERY DAY you need to pee...A LOT), and exercise (some sort of aerobic exercise for 30 minutes a day). I've done many experiments of how to get clean, and ive found that this is not only the safest, but quickest and also surefire way. I smoked a blunt with 3g of chron in it, did the above system, and 3 days...well 2 and a half cause i took it around noon the third day....i was clean.