If we're still talking about providing housing, then nobody would be giving them money directly. You're thinking of UBI, which is a separate conversation.

Regardless of whether we're still talking about housing or cash, requirements like "are they messy" or "are they on drugs" have been tested and shown to be ineffective and harmful.

My personal opinion about these facts is that they're rightfully bitter about the hand they've been dealt, and stop littering once they've got a stake in the community. It's absurd to be mad about someone leaving trash on the street after we've left them on the street like trash.