STOP! Find another drug. Most drugs leave your system in a few days. Get some acid, they can't test for acid. Just stay away from the ganja.

9 months might seem like a while but it will pass, and you'll be able to come back strong:rasta:

Substitution can be very sketchy. I don't know what your on probation for, but the last thing you want is to take a misdimenor offence and add a felony tampering charge to it (trust me, that's my position). My advice... ABSTAIN.