About 3 years ago we had a CO and an elder turn up unexpectedly on our doorstep. "We just thought we'd give you a shepherding call when we are in the area," said the elder.
So I said directly to the CO that I understood shepherding calls had to be scheduled with the individuals in advance. He agreed. I said so why hadn't they done it. Still, said the elder, since they were here maybe they could just step inside anyway.
To that I said no. It didn't suit as we were busy. But I hoped they'd have more success on their next call. After looking one to the other, they turned away and left.
That is the last time a CO plus elder has come back to our house, even when we see through the window that they are visiting other JWs who live very close by us.