1. If clothing is made of wool, silk, or other delicate materials, we can choose bleach or stain remover, but these two types are also different. For example, if there are obvious stains on the clothing, it is best to use stain remover. After washing, check the effect. If it is not white enough, we can use bleach again.

2. Regarding whitening soap, it is generally not suitable for areas with hard water quality, as hard water can produce a large amount of calcium soap, forming a layer of gray white suspended solids on the water surface, which can easily stain clothes and cause them to not be washed clean. Composite soap with calcium soap dispersant can be appropriately used in hard water areas.