Trust usually works better than policing. Because policing someone, or having an "accountability partner" just assumes that yep, you're a vile old sinner, and you would love nothing more than to grab that bong and get stoned as a rock. Trust, on the other hand, believes the BEST about a person (just like Paul described LOVE in the bible!) and will actually inspire people to get BETTER.
You can force me to stop using drugs, but you can't change me from an addict to a free man. You can modify my behaviour, but not my identity. So it doesn't really fix the problem, it only makes it look better. Having an "accountability partner" is one of THE most unbiblical concepts ever made up, and I guarantee you it has never, ever, set anyone free from any sin. It cant. It's useless, it turns people into whitewashed graves.
God does the exact OPPISITE of an accountability partner. He doesn't say "I saw what you did there," but "hey, look what JESUS did HERE!" - and that's the only message that can save addicts like I used to be. I could take the courses and grades and learn to live with my addiction, I could go to church and learn how to please the christians. Or I could go to God who could actually make me a NEW person. Unlike men, God already saw me, and treated me, like a GOOD and FREE person. And thus I BECAME a good and free person. You see, just like when He created the world, there may be emptiness and void, but when God speaks, stuff happens. When He says something is so, it IS so. Go to people and they will call you an addict and try to fix you. Go to God and He will create a whole new person.
All that said, it's obviously good to have a person you can share your wins and losses with, someone to confess to when you need it. But you're not accountable to any man.