I got Cryptwall and don't want to take a chance of infecting my external usb drive.
What's the bug being reported?
Are you attempting to ask the question posed in your subject-line?
If so, I assume this would work, though, without either doling out Malware advice (forbidden on the forum) or suggesting competition per se, You're better off making (on a separate pc preferably) a Derek's DBAN live cd and wiping the drive that way; malware can hide in RAM and reapply itself within windows sessions.
If you're trying to wipe a system drive (it's far from clear what you are proposing) then no, CC won't do it for a start, and if it did then it wouldn't like the O/S disappearing from under it's feet.
If it's not a system drive then you can run CC from anywhere (else).
Why not just format the drive. If you run a low-level format (or whatever it's called, the long one) then all sectors will be set to zero (post XP). More or less fool-proof.