From what I know (or think I know) about weed in your system is that cannabinoids adhere/bond (whatever) to fat cells in your body.
I know heavier people that have gone in for piss tests at 6 weeks clean (not smoking or ingesting cannabinoids), and they still piss dirty.
Myself, I have pissed clean in under 3 wks. I eat garbage fast food 80% of the time but I have an extremely fast metabolism, and have little to almost zero body fat.
I lucked out in that I was never tested by my PO, but I do have to take the tests often because I work in the oil patch. I have had to go into professional health centers and go thru all the steps, and I have had casual conversations with nurses there and learned a fair bit.
I even snuck a synthetic urine belt with heating pads into the clinic once, and passed with it.
More than likely, if you even get tested at all, you are going to get a 5 panel or similar test. It will test for Cocaine, Opiates, Amphetamines, MJ and PCP (never even seen PCP in my 2 decades of drug-dom so why the fuck they test for it up here I have no idea)
More than likely, they are NOT going to pay for a lab test, so synthetic urine could be a workaround. However, synthetic urine, or even frozen clean urine should be within about + or - 1.5 to 2 degrees of typical body temperature of 98.6 degrees.
Some people naturally run hotter or cooler than average, or health conditions may vary the temps, but a variance of more than a degree or two screams out.....test me again, or even fail me.
Another thing to know is that some newer 5 panel tests can now detect masking agents/flush solutions.....I was told this by the clinic lady as she was testing the synthetic urine I just filled the cup with....LOL
Cranberry juice works well to flush your system if you want to speed the process up.
NOW.......all that being said......listen to what some of the others have said......if you can tough it out and go clean, that is the BEST way to keep your ass out of jail.
The stuff I told you should only be considered if you make a mistake or have trouble stopping.
Good luck, and I hope you have as much luck as I did.