You seem to be using a different definition of scrubbing than people talking about filesystems usually use.
Scrubbing means to read all the data off a filesystem and compare it against its checksums, so that you are confident nothing has happened to the data (hardware failures, cosmic rays, whatever).
ZFS and btrfs have specific scrub commands that do that.
There's no scrubbing available for a system which does not keep some form of checksum/crc/hash of the data.
I think that you are talking about secure delete procedures.
Scrubbing means to read all the data off a filesystem and compare it against its checksums, so that you are confident nothing has happened to the data (hardware failures, cosmic rays, whatever).
ZFS and btrfs have specific scrub commands that do that.
There's no scrubbing available for a system which does not keep some form of checksum/crc/hash of the data.
I think that you are talking about secure delete procedures.