Wiping a BitLocker Encrypted USB Drive - Possible?

Only for the record, here is some discussion on the various related Registry settings (some of which are used in some WinFE versions) and other related stuff/tools
http//reboot.pro/topic/19687-winfe-sanpolicy-and-noautomount-combinations/
http//mistyprojects.co.uk/mistype/mini-winfe.docs/readme.files/diskmgr.htm
http//reboot.pro/topic/21481-is-the-disk-really-write-protected-possible-windows-api-bug/

Also, JFYI, Dynamic disks (rare as they may be in real world) seemingly behave slightly differently (though this is related to the opposite issue, having a volume read only)
http//reboot.pro/topic/15883-winfe-dynamic-disk-problem/
http//reboot.pro/topic/18882-some-questions-and-sanpolicy-values/

jaclaz

My standard approach to recalcitrant devices is to connect the device to a Linux machine, unmount if it happens to automount, then simply DD /dev/zero to the drive /dev/sd{letter} no number as you want to target the device and not the partition.

You don't even need to spend time zeroing the whole drive, a few seconds is sufficient to destroy the file system enough that it will be seen as an unallocated device that can be reused as desired.