Q: Washed my nano....any chance of it working again?

Almost certainly, no.  Sorry, but it almost certainly is fried beyond recovery after a complete, long immersion like that.

You can try and dry it out in a bag of uncooked rice.  Change the rice every few days, but I would leave it in there overall for at least a week or two even.  If there is any chance to dry it out, and it is is not already shorted out beyond hope, that is all you can really do.