Back in the day out of college, I found out a week before I needed to take a drug test. Bought one of those "48 hour" kits. Comes with home tests, and basically lots of pills. But it all comes down to drinking a ton of crap non-stop for the 2 days to flush your system. Doesn't really flush your system, but flushes it enough so that the next time you pee its clean.
But if you are looking for a job, you're dumb if you don't quit. You never know what a potentially employer may want, or how fast they want to move. Once you have a job, go nuts. Start looking for work, be smart. I used to partake in the gange back in the day - but its too risky now. If it was legal, or if I live in Cali, or if I was still in college, may be another story. Not worth my losing a job now.
But to the OP - I've had success getting the next day order of a 2 day kit. Try that, lots of cranberry juice - and I believe my father recommends lots of Tums...he has some home recipe for this that I'll have to look up.