Also wanted to add that in some states you can buy a small amount of weak codeine cough syrup OTC. It's a Schedule V substance, and you have to sign the register, promising that you will not do this again for x amount of hours. In NJ, you can buy 4 oz. of Robitussin AC (weak, but it would give you an excuse for passing the test if you didn't want your doc to know about OP's). That was around March, and you're only allowed to do it twice a year here; you gotta also find a mom-n-pop pharmacy that's willing to sell it to you. The big chains certainly will not, but you just gotta look, there are plenty of other places that will.

-yawkaw