You're on the right path.
This will wipe out anything:
rm -rf /path/to/folder/
the r is for recursive (go into subfolders to zap stuff in them too)
the f is for force (get rid of it and don't talk back)
You need to own the files you are zapping so to be sure do it as root.
sudo rm -rf /path/to/folder/
BE VERY CAREFUL WITH THIS!
When you hit the return key it does it without asking questions.
If your not careful you can wipe your whole disk out. as in rm -rf /
Sure, you can do it with the 'boot into 9' thing and that's the safer way to go, but that won't get you your 5 UNIX Guru points.