Niacin to pass drug test?

Ok so my stupid *** boyfriend is trying to get a better job and they drug test.. According to him he can still smoke all he wants then take a niacin before the test and he'll pass... Umm I think he's a ****** idiot.. Excuse my language... I don't understand why he can't just quit for a month.. Wouldnt tht be th easy way..?? I'm about to be done with him! I think its all bullshit.. We have a child together I'm going to college and all hes doing is workin aat taco bell not making ****! He always says he puts family first but if tht was true wouldnt he stop smoking so he could get a real job..?? Sorry for so much detail im just extremely pissed right now.. So ne ways what are the chances of him passing if he takes niacin and wouldnt niacin show up on a drug test too..??