Using someone elses urine to pass...how long will it stay "usable"

[teddybearpicnics]

Swim has to take a drug test for his probation and had someone else piss in a cup for him 2 weeks ago, he has kept it at room temp since then, will it still be good to use if he tapes it to his leg with a heating pad to keep it at the right temp? or will the "control" part of the test not pass because some parts of the urine may have gone "bad"? he has to take the test in 5 days, so the piss will be almost 3 weeks out of the natural body. Any help and/or tips would be appreciated.