Is saltwater used for personal hygiene agriculture manufacturing?

Saltwater, usually as a brine is used in many manufacturing processes. As to personal hygiene? Possibly, but the salt left on your hair and skin would need to be washed off with fresh water. As to agriculture? No, I don't think that crops would appreciate the use of a salty solution, and would probably die if the solution was too strong, or fresh rainwater was too long in diluting the salt content of the soil. Some plants are more tolerant of salt than other plants!