How To Create Non-Persistent LiveUSB

It seems that for 11.4, the default is persistent mode. Can anyone help me to change to non persistent?

I created the LiveUSB by downloading the ISO and using dd to transfer into a 16GB thumbdrive. I would like to use the remaining space for my own files. After formatting the secondary partition as FAT32 and rebooting into Live mode, it seems the persistent mode is back again.