wipe freespace on ext3?

[defcon <defconoii gmail com>]

Hey all, I have failed at wiping my freespace on my hard drive, what I
have done is:
[dd] if=/dev/urandom of=bigfile
and I also have tried sfill from the secure delete package from thc.
I have successfully recovered all deleted files after wiping the hard
drive with foremost, since this is a journaling filesystem is there
any way around this, is anyone experienced in this and have tried to
wipe/recover files on ext3?
Thanks
defcon