If you’re like most people, you probably take your pillows to bed with you. But if you’re like me, you probably don’t have a bathtub. So how do you clean a pillow in a bathtub? The best way to clean a pillow in a bathtub is to use warm water and soap. Soak the pillow for about 10 minutes, then dry it off. You can also use a vacuum cleaner to clean the pillow.