I think they may have found a night or two in a Port Hedland lockup to be "culturally enlightening".
And if immigration and the local magistrate do their job then they will spend waiting time in custody, be put onto the next available PHE - DPS flight (not that frequent), and all at their own cost plus penalties.
I will try to follow this one up for actual outcome.
I can see no reason at all why they should not forfeit right of entry to Australia, for instance.