Well according to this
I understood it as a necessity. Or at the very least, a much easier way of doing it with Kubrick.
Firmware 5.3.2: use the manual method.
The only difference being, I saw the update to that post, which suggested using the Kubrick method which downgrades and Jailbreaks automatically to 5.1.2.
Oh well, as long as I haven't done anything terrible to my Kindle, I can handle a quick re-install of Duokan.