So you tried NiLuJe's "kindle-5.4-jailbreak.zip" method for firmware 5.0.x-5.4.4.2 devices.
I assume you properly unzipped the "kindle-jailbreak-1.14.N.zip" file, and then unzipped the "kindle-5.4-jailbreak.zip" which it contained, and then copied the multiple files within to the root of your Kindle... just like the instructions said?
So, what happened when you tried to use the Update Your Kindle menu?
And, did the files you copied disappear?
And, what is the exact error KUAL gave -- none of that "something" error, please.