Has any body else heard that a 1/4 cup of apple cider vinegar to a gallon of water for one week will naturally get rid of round worms with no withdraw period
ACV helps in calcium absorption and lower gut Ph to help with bacterial issues as well as other benefits, but not a wormer. A tablespoon or 2 should be used per gallon of water, not 1/4 cup.
Metal waterers are usually galvanized (zinc coating).
Adding vinegar to the water makes the water acidic which in turn will corrode away the coating possibly to the point that the water becomes toxic from the zinc.