There is one way I can see the military option having good results--create something akin to the French Foreign Legion.
Let people enlist in such a unit with none of the usual background checks, et cetera. They don't even have to use their real names. Whatever name they use when they sign up, they can continue to use when their enlistment is up.
It would give some people a chance for a clean break with a screwed up past without undermining the professionalism of the regular military.