I think a better solution would be to tell them what we used to say when it was time to close the bar. "You don't have to go home, folks, but you can't stay here."
In the case of this obviously retrograde belief, why not just say, 'You don't have to give up Islam, but you can't practice it in our country.'
In other words, boogy on out of the country and find one that wants to commit suicide with you. Clearly we don't.
If all nations followed suit, the whole clan would eventually be isolated in one region where they would be able to finally destroy each other, no longer having access to the civilized world to get their human sacrifices.
But before you condemn me, keep in mind that this is exactly what Islam has in mind for the world.
Disregarding the fact that certainly, this is not the view of all or even a majority of Muslims, Yes, the radical ones are, and I notice we are at war with them for it, and consider ourselves to be justified.
And we are justified. But we wouldn't be if we did the same thing they are doing.