Rinse peanuts in colander. Place in Large(family-size) slow cooker. Pour salt over peanuts. Add water to just cover peanuts. Place lid on Slow-cooker. Set on HigH.
Cook 12-15 hours--depending on how soft you like your peanuts. I fix my Late afternoon/early evening, and they are usually ready the next morning. ***You may need to add additional water during the cooking time--watch to see if too dry. Often, after cooking all night, I will set the cooker to low/keep warm, and the family will nibble on them as they choose during the day.
Drain and freeze in zip lock bags, if desired.