you will have to make sure the initiators are de-registered in connectivity status,
pretty sure you have to be in Engineering mode.
once they are disconnected physically and de-resgistered you should no longer see them.
if they are no longer in connectivity status but you see them under the hosts tab then they are considered Ghost entries. for the ghost entries you can try restarting the management servers of both SP's
http://IPaddres/setupif that does not remove them the SP's will need to be rebooted. you can reboot one Stroage processor at a time, this will remove the ghost entries