Being able to use a debit card time does not prove he is capable of paying the rent and utilities on time, and making smart decisions about the small amount of money that is left over. Unless he's getting food stamps, or whatever they call it these days, groceries would be an important part of the budget he'd be responsible for.

Why not do a small test. Give him a week's worth of the grocery budget and see what type of choices he makes.

Having a debit card would allow him to withdraw all his benefits in cash for the month, the first day it is deposited. Can you trust him enough to give him the cash for your rent and that he'll get it to your landlord?