Heat 'n Kleen kettle cleaner is for use inside your kettle and is designed to remove grease and carbon easily. Its outstanding detergency emulsifies grease and oil and will soften hard carbon deposits. Never submerge your kettle in water. Heat'n Kleen is for use inside the kettle only. Cleaner comes in 31 oz. containers To use: Use 2 oz. of Heat n Kleen per gallon of water for moderate soils. For heavy duty cleaning up to 4 ounces may be used per gallon.