Encrypting entire bootable drive

Hi,
I have a USB drive with kali 2017.1 ISO ready to go.
I'd like to encrypt the entirety of the drive, with all spaced used for a single partition that includes the OS.
I'd like to figure out a way to setup a nuke password for this drive.
This may not work with luks nuke (cryptsetup) method given in the kali docs section... maybe it will hour, hoping for some ideas. I'm open to other solutions including a grub loader on the stick, as long as the goal of nuking the entire install is achievable with a nuke pass.
I would like the single partition to be persistent on the stick only.



Another related question, what are some creative uses for the other keyslots in luks nuke feature?:D