[jonathanstrange]

> It's trivial to lock the USB stick in such a fashion as to be impossible to decrypt in a practical time frame.

That is definitely not true if your adversary has the ability to control the endpoint and might even reflash the firmware of your USB stick.

If you use OTPs in such a threat scenario it's safest to use old school easy-to-burn paper OTPs with manual encoding/decoding.