I've only used three programs to fool around with doing this, and so far, I can't tell if they did the job or not, but they have a "Government Whipe" standard. They also cost money.
The first product I used was
Norton Wipeinfo. Norton Wipeinfo is, unfortunately, part of the Norton Systemworks suite, and that is enough to make it not worth installing. However, reviews have stated it does the job, and if you really need it, it may be worth installing it alone.
Norton Systemworks Premier
Next is McAfee Shredder. McAfee Shredder comes with Virusscan Pro, and along with Quickclean (also included with VSP). This basically does the same thing that norton does, with the government wipe, and is strikingly identical in terms of operation. It just looks different
McAfee Store Link, check out the learn more for VSP
Lastly, there's PCTools privacy guardian. Now, to be honest, I stopped using it two versions ago, so I don't know exactly what the most current version is like, and how it works. I do know, that it used the same type of government wipe setting system. Should you decided to concider this option, download the trial first and see if it is what you need.
PCTools Privacy Guardian
I hope this has helped.
sc7