Error creating zfs pools using drives that belonged to a md raid array

While migrating a file server from mdadm software raid to zfs I encountered the following error while creating the pool:

zpool create -f tank mirror /dev/disk/by-id/xxx /dev/disk/by-id/yyy
the kernel failed to rescan the partition table: 16
cannot label 'sdb': try using parted(8) and then provide a specific slice: -1

Even if the old mdadm array was no longer being mounted (as more than one disk was missing and it was a raid5) they were still being added to md0:

cat /proc/mdstat
Personalities : [linear] [raid0] [raid1] [raid10] [raid6] [raid5] [raid4] [multipath]
md0 : inactive sdd1[4](S) sdb1[1](S)
3907025072 blocks super 1.2

unused devices:

The fix was easy enough:

mdadm -stop /dev/md0
mdadm: stopped /dev/md0
zpool create -f tank mirror /dev/disk/by-id/xxx /dev/disk/by-id/yyy
zpool status
pool: tank
state: ONLINE
scan: none requested

zpool label clear was mentioned as a fix for this error and I tried that without success before realizing that the drives are still added to a md array.