Two days clean is not very much sobriety on which to make a commitment, like paying for an apartment for them and expecting them to stay clean.
I agree with all of the above, the "real" help is out there, available to them through Salvation Army and many other organizations. If they want help they will go for it. If they don't, you just saved yourself a whole lot of rent money.
Please be careful with your own part in all this. Support their "actions", not so much their words.