Just flush it thoroughly with a hose.
When I studied auto mechanics and we spilled acid on our cover-alls we quickly flushed it with water.
Nine times out of ten it did not damage the cloth, just uncomfortable wearing wet clothes.
It is a liquid that is diluted by a liquid including morning dew; after a week even if you dug up the dirt and rubbed it on your skin not much would happen.
Battery acid has only 4 moles of acid per liter of water; most concentrated acid used in labs is approx. 17 moles per liter.
