I can't get it working.
I create folder in documents (F:\documents\Calculated in death), than I put *.mobi file there. Turn on kindle, than plug it back to PC. Now I have this folder
F:\documents\Calculated in death\Calculated in death.sdr I put x-ray file there and it looks like this
http://i.imgur.com/kOZBGiJ.jpg or this
http://i.imgur.com/nSbkqGi.jpg.
I tried website, calibre plugin and x-ray generator. I just have greyed x-ray button.
My x-ray file
http://pastebin.com/VbrERT57 for HG.