Riparare la chiavetta USB non cancellabile

Quindi, ho un Apple USB Thumb Drive modello USB A1384 , e mi piacerebbe cancellarlo (in particolare, per creare un simpatico stick per l'installazione USB di macOS Sierra con marchio Apple); sfortunatamente, non sta andando bene adesso:

> diskutil list
/dev/disk0 (external, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *1.9 TB     disk0
   1:                        EFI EFI                     209.7 MB   disk0s1
   2:                  Apple_HFS Kate's HD               1.9 TB     disk0s2
   3:                 Apple_Boot Recovery HD             650.0 MB   disk0s3
/dev/disk1 (external, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:     Apple_partition_scheme                        *8.1 GB     disk1
   1:        Apple_partition_map                         30.7 KB    disk1s1
   2:         Apple_Driver_ATAPI                         2.0 KB     disk1s2
   3:                  Apple_HFS Mac OS X Install        4.2 GB     disk1s3

> diskutil eraseDisk HFS+ %noformat% /dev/disk1
Started erase on disk1
Unmounting disk
Error: -69877: Couldn't open device

> diskutil unmountDisk force /dev/disk1                  
Forced unmount of all volumes on disk1 was successful

> diskutil eraseDisk HFS+ %noformat% /dev/disk1          
Started erase on disk1
Unmounting disk
Error: -69877: Couldn't open device

Qualcuno sa come posso riparare / ripristinare questa unità? Mi piacerebbe davvero usare questo disco specifico , per ovvi motivi; quindi "comprare un nuovo disco, sono economici" non è davvero una soluzione.

Output del profiler del sistema :

USB DISK:

  Product ID:   0x1502
  Vendor ID:    0x05ac  (Apple Inc.)
  Version:  11.00
  Serial Number:    AALQTJD76ZNBBARF
  Manufacturer: APPLE
  Location ID:  0x00300000
  Capacity: 8.1 GB (8,103,395,328 bytes)
  Removable Media:  Yes
  Detachable Drive: Yes
  BSD Name: disk1
  Partition Map Type:   APM (Apple Partition Map)
  Volumes:
disk1s1:
  Capacity: 31 KB (30,720 bytes)
  Media Type:   Unknown
  BSD Name: disk1s1
  Content:  Apple_partition_map
disk1s2:
  Capacity: 2 KB (2,048 bytes)
  Media Type:   Unknown
  BSD Name: disk1s2
  Content:  Apple_Driver_ATAPI
Mac OS X Install:
  Capacity: 4.19 GB (4,190,658,560 bytes)
  Available:    374 MB (374,026,240 bytes)
  Media Type:   Unknown
  Writable: No
  File System:  HFS+
  BSD Name: disk1s3
  Mount Point:  /Volumes/Mac OS X Install
  Content:  Apple_HFS
  Volume UUID:  34411C5B-BDF3-3716-B130-572745C66DEE