Whenever I use Killbox I use the Delete on reboot option and none of the others. My apologies if you've already tried that option but it's not in your images.
My main method of deleting seemingly undeletable or locked files is to use Unlocker which, thankfully, has recently gone 64 bit compatible. I was lost without it.
Glad to have helped.
I originally only downloaded Killbox because, at the time, Unlocker wasn't 64 bit compatible and Killbox could delete files during re-boot, i.e. when they weren't being used by anything.