I don't think the idea will work as well for jihadi's the way it does for normal crime, many Europeans going off to fight with ISIS were not considered outsiders many had jobs, decent level of living and until they turned extremist had even become pretty western. This is an ideological war standard of living won't change that.
I think this has more to do with the way the world is today, people especially men have always run off in search of adventure, many have gone and fought wars in other countries, during the times of Empire men could go off explore new countries, fight in battles and make their fortune. In this day and age there's very little adventure or glory for young men, then these young guys get these extremists telling them stories of glory and adventure and how they will come back heroes with tales to tell and get sucked in. It's also why so many want to come back when they realise the reality of the situation.
Those that have dual citizenship are having their British passports taken away, those that don't are more of an issue, we didn't jail every Nazi soldier so it's difficult to prove anything other than they need to be watched very closely. It requires a more long term solution, the modernisation of Islam to bring it out of the dark ages, whether that's possible I don't know. In the UK I'd like to become a secular country, no religious rights in public, work or government buildings only in your own home.