Combine the flour, salt and boiling water in a bowl. While the water is hot, use a whisk to combine everything as best you can (it's going to thicken quickly). When it’s cool enough to touch, use your hands to knead the ingredients into a dough.Add the essential oils and optional ingredients (like flower petals) and continue kneading.Break off 1 to 2 inch pieces of dough and roll with your hands until it forms a ball. Press the ball slightly until it resembles a stone.Place on a baking sheet lined with parchment paper and let dry overnight.Combine the flour, salt and boiling water in a bowl. While the water is hot, use a whisk to combine everything as best you can (it's going to thicken quickly). When it’s cool enough to touch, use your hands to knead the ingredients into a dough.Add the essential oils and optional ingredients (like flower petals) and continue kneading.Break off 1 to 2 inch pieces of dough and roll with your hands until it forms a ball. Press the ball slightly until it resembles a stone.Place on a baking sheet lined with parchment paper and let dry overnight.