I want to document how I did this in case I need it in the future. This is a good way to wipe an entire drive quickly with any Linux LiveCD or USB stick. It only uses a program called dd.
Most computers, the primary hard drive is /dev/hda. So, to wipe it, issue this command:
dd if=/dev/zero of=/dev/sda bs=32M
Note that 32MB is a good buffer size for most modern drives. I'm getting 100 MB/s speed wiping using this. For a 500GB drive, that's taking me around 1 hour to wipe.
You can optionally check for a status in a separate terminal tab like so:
while true; do kill -USR1 1234; sleep 5; done
Replace "1234" with the PID of dd (which you can get with a "ps -A | grep dd"). When you flip back to the tab where dd is running, you will get a status update every five seconds. It tells you how much data has been copied, as well as your bytes / sec copied.