If you do drugs and need to pass ampiss test, a P-vac isn't an option and you need clean urine, you'll need to do an oil change. An oil change is when you stick a sterile tube in your urethra until urine naturally comes out. Next take a syringe full of clean urine and inject it into the tube. There, your oil is changed.
The test is tomorrow, we'll never pass unless we do oil changes.