Hairspray does wash out with water. Fortunately, removing hairspray from your hair is generally pretty easy. If you don't have many tangles in your hair, you don't even have to use water to remove it.
You should be able to remove the hairspray by brushing it out. However, if you use hairspray frequently, your hair may experience product buildup, which requires more work to remove.
Hairspray works by creating polymers that coat the hair bonding them in place. So, whether you have used hairspray that has left your hair feeling crunchy or not, you still need to remove it to keep your hair fresh and healthy.
Hairspray will typically just brush out. You can take a comb or a hairbrush and brush the product out, and your hair should feel almost, if not exactly, how it did before you applied it. If you had a firm hold hairspray, you should notice a difference after brushing. Whether brushing out hairspray is a good option for you depends on how much you've used.