Of course! A pinata. Why didn't I think of that? I had thought of blowing eggs and letting the kids paint them, sort of a fun, Spring is coming activity, but I don't like the thought of 20 kids running around my house with paint. The beads might work out better. Or, I could let them decorate cookies and take them home with them.
We don't live near a hot spring, at least not that I know of, Friend of Mine, although it sounds like it was a really cool party.