[treis]

Only if you're sure 1 -> 0 is not detectably different from 0 -> 0.

There's almost certainly secure ways to delete. But not worth it for a five year old drive that may have had sensitive information on it.

[Gordonjcp]

How could they possibly be detectably different?

If you're saving stuff on old MFM drives today, you're probably not in the demographic that cares about wiping drives for disposal.