What I'm looking for is something that is smart enough to find "empty" space on a hard drive and do a secure delete on that space, leaving existing apps and data alone.
SRM wants you to provide the directory path manually, Disk Utility looks like it would erase the entire hard drive, and Secure Empty Trash only works on the Trash folder and not fragments of old files that could still be outside the Trash folder. That's what I'm gathering from what I've read, anyway.
Thanks for anything usefull.