Soap and nitre, also known as lye, or anything else we use to cleanse ourselves, contains Hydroxyl (OH). This is frequently in the form of Sodium Hydroxide. It's part of a definition of the Hebrew word for soap.
Sodium Hydroxide
Lye: בַּנֶּ֔תֶר – Nitre, nether
We've frequently heard it said that the Bible isn't a science book. Many of the people who say this are Christians. We disagree, but we can understand why people, even Christians, would say this.