warning use at your own risk
Make a backup of your personal data befor clean up the live USB Stick
user@gecko-lab:
user@gecko-lab:~$ lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sdX 8:16 1 29.2G 0 disk
├─sdX1 8:17 1 4M 0 part
├─sdX2 8:17 1 44M 0 part
├─sdX3 8:17 1 10G 0 part /lib/live/mount/persistence/sdX3
└─sdX4 8:17 1 10G 0 part /lib/live/mount/persistence/sdX4
user@gecko-lab:~$ cd /lib/live/mount/persistence/sdX4
user@gecko-lab:~$ sudo rm -rf rw work