I am a trans-OS user (coming out, I love linux and windows, one with the heart and both with the mind ;))
Somewhere in the back of my head I remember, formatting an external usb drive with windows or on windows with third party software; basically just plugging that drive to a windows machine makes something to the drive so it will never forget windows again. I actually don't believe electrical current running through windows is anyhow biased...but...
What is the most innocuous strategy to prepare a factory blank external (trans-) usb drive for windows, linux and if feasable any OS else?