Just took delivery of a used D3. I want to completely wipe out the previous owner's settings, etc. Doing the two green button reset doesn't seem to do the trick. Is there a more extreme reset that will set it all back to factory?

I don't think there is. You can try flashing new firmware that you download from the Nikon support site.

I remember when I got my used D700, there was no way to do it.

Same thing with my D800.

Tried reloading the firmware... no dice

Got this from the manual.

Go to the shooting menu, highlight "Reset shooting menu" click OK, then click "yes"
Next go to the custom setting menu, highlight "reset custom settings" click OK, then click "yes"

Both will be set to default.

I did that too, but the previous owner's titles of menus and settings remain...

You will have to rename the banks your self. Can't find a reset for that in the manual. Default names are A,B,C,D. You will probably have to going to each bank and also do the reset like above.

Is this your first camera with a dedicated OK button?

The middle button on the selector isn't the same as actually pressing the OK button.

Had to get use to that when formatting cards in camera, use to always keep hitting the middle button on the selector instead of OK.

I specifically remember having to delete the prior owner of my D700's copyright info because I could not find a way to reset it...

Sorry you're out of options...

Thanks everyone, yeah, spent about an hour last night wiping everything out, etc. I'm all set now.