OP if you want good coke it would be far less effort to just buy like an 1/8th and re purify it, and then cut it like 50/50 or something so its safe. Don't hold on to the 50/50 being safe as a fact you should probably research that, I just know that you can re purify your coke and its not supposed to be that tough.
Google it.
If you want good coke that is probably your best bet