Second machine, third drive will work, but simply adding the -R option to a zpool import command works fine. -R is "alternate root", a different mount point. The OPs problem was he typed in zpool create instead of zpool import and didn't catch it until after hitting enter.
Mountpoints are cheap, so one way that may have been easy to follow would have been to do the following as root:
zpool import -R /oldtank /dev/adap0
than all zfs filesystems/dataset would start at /oldtank, they could have been copied/zfs sent where they needed to be, then zpool export and zpool create to clear the old drive.