Five Star Chemicals Beer stone remover in a 8 ounce squeeze bottle is good for removal of beer stone and scale.
Directions: Use at rate of 1 oz. per gallon of water. Allow contact time of 10 min. Drain and allow the surface to air dry. Rinse and sanitize just prior to next use. For stubborn scale or stone follow standard instructions but do not dilute. Apply full strength to area.
Beer stone remover is great for hard to clean kegs, lines, kettles and more