Ok so I have a garauntee'd job driving dump truck, 24 bucks an hour to start, 29 after 3 months

I have to piss clean first. I havent smoked anything for 7 days now, and I have another 8 or so days before I have to go for the drug test. I am slender, 5,11" at 145 pounds. I'm pretty sure I will be clean in 8 days, but before I quit 7 days ago I had been smoking non stop everyday for at least 3 years. To be sure I was thinking about doing some sort of week long detox kit. The kind that cleans your liver and whatnot. Would this type of product help to remove thc from my system? Do any of you have experience with detox kits? Any advice you guys could send my way is greatly apprecciated. Thanks in advance.