Reference: I'm doing this (probably 7 pass) to ensure a thief didn't install tracking software on my Pro before it was recovered. He knew I had LoJack on it (long story) which creates an undetectable partition on the HD that won't go away with a simple reformat, so I'm mildly concerned he could've installed some different bit similar software.
This should help
It has the instructions to restore the entire system from a backup farther down on the page.
Also, when you start your system from the external drive, you will be in the OS that's backed up, and you can then from in disk utility wipe and erase the internal macbook pro drive. Single pass should do just fine as you will be overwriting it with your backup next. Then restore the backup to the macbook pro.
This post has been edited by icerabbit: 08 February 2013 - 04:09 AM