Yes, it should; however Eraser can only access those parts of the host drives that the file system can actually see. If, by 'wipe the drives', you mean everything on them, you could consider removing the Raid array, then mounting the drives in a caddy, formatting them, and then wiping them. More work, but the wipe will then cover all but the sectors marked as bad, which are, by definition, inaccessible to the OS.
David