Sorry, follow @Wyorp Rock's instructions, don't spray. She is an Educator, listen to her.Boil a quart of water and let it cool in a clean container like a glass quart jar. Add 2 tsp salt and a pinch of baking soda. Put a clean lid on it and shake till salt dissolves. When cool, place in a CLEAN (or new) spray bottle. And yes, it is perfectly safe to use as long as you don't let it get contaminated. In fact it is much safer to use than just tap water.