So I've been trying for about a week. I can get Kali to boot but not with persistence. I followed the guide on Kali's website as well as many YouTube videos. I'm working on OS X El Capitan. When I follow Kali's steps when I get to

read start _ < <(du -bcm kali-linux-1.0.8-amd64.iso | tail -1); echo $start
parted /dev/sdb mkpart primary $start $end

It says the Kali Iso file can't be found. I am using the right file name when I do it (Kali-Linux-2016.1-amd64.iso. So I stopped trying to do that. I went on gparted and with the remaining 13 Gb on my 16 gb flash drive I went into terminal and did all the /mnt/my_usb stuff with the persistence.conf file saying / union but that doesn't work whenever I boot up again the drive is still in the corner just with that file. Can anyone give me a detailed summary on how to do this or link to somewhere with instructions to help? Also, does anyone know why it's saying it can't find the iso file when I'm in kalis terminal doing the parted command thing?