We use Borax for soap, it is not what you would consider a plant/tree product. Deposits in/on the earth are used for many things….the only fear of using these minerals is the process/packaging by the manufacturers and often if they think a human is going to consume something, they deliberately poison it: 2 examples- Iodine and turpentine. 2 products humans use to use internally. Many books have been written promoting all sorts of solvents, soaps, etc……which have made people drink their pee and even drink chloral bleach as they seek the cheapest possible treatment they can obtain….when in doubt---rule is go slow or pass. I remember when idiots sprayed W D 40 on their hands for arthritis and swore it was a cure….