Are bath bombs bad for your tub? Bath bombs not any worse for a bathtub than any other soaps or chemicals we put in them. But, wherever there are bath bomb reviews, there seem to be reports of people experiencing staining. So, the worst that can happen is some staining from brighter-colored bath bombs. The good news? The coloring used in most bath bombs will wash right out of the tub so the staining is usually never permanent.