Wow, you guys have bad/crooked banks. My bank doesn't have a publicly accessible machine in the lobby. I have to give my coins to a teller, who processes them behind the counter, in full view where I can see them. They then return any coins that stick to the magnet or get rejected to me. What's so hard about that?
Three of my credit unions have coin machines, all no charge and all return the rejects to me. Even my fee charging(5%) bank has a reject slot that spits back the Canadian.
It looks like to OP may have read this article http://blogs.app.com/pressonyourside/2012/06/26/can-you-trust-a-counting-machine/