McLube
Try McLube, you can purchase it in quart and larger containers. Then just put it in a spray bottle or garden sprayer. They use it on sails and hardware, don't see why it would not work on the lines. You can also try removing the lines from the boat and washing them in a washing machine. Use some mild soap like Ivory flakes. Let them air dry and then you can try the McLube treatment. When you wash the lines be sure that you coil them up and tie them off DO NOT just throw the line in the washer.
