if its been through the washing machine its probably knackered, ive saved a phone with the rice method after dropping mine in a pint, but it was only submerged for a second, yours has been submerged and banged about in hot and cold water for an hour.
Try it, but youll probably find your efforts will be in vain.
Rice and Airing cupboard are all you can do. Don't turn it on for a week. DO NOT take it back and claim it just stopped working. Water damage is easily detectable.