My sister Carrie is always telling people to eat rocks...and although my daughter is too young to know what that means and has never heard her say it, but she sure loves to try it. At first I chased her around and kept pulling the dirt out of her mouth but after awhile I found that it was a useless endeavor. So, I just made sure that she didn't have any rocks in her mouth to go along with the dirt.
Plus, kids eat dirt all the time and that is nothing compared to what one of my nephews did when he was at the crawling around age. He got into a litter box and helped himself to some cat droppings and my sister completely freaked out and made our mother clean him up.
So, I figure dirt is nothing compared to that!!!