I don't know where your church is but individual homeless people may not be able to trek around town to visit one of your rumble sales or even know that they're taking place. Perhaps sorting for durability and insulation (rather than fashion value) and driving around with a pickup asking people if they need warm clothes would be a more effective approach.

Feel free. The point is, the clothes are not the issue. Its the effort it takes. There are places that do that (Salvation Army etc) and they have absolutely no trouble getting clothes.