Be careful!
Careful with the washing machine!! Loose rope in the washer can get tangled in the machine and freeze the agitator.Best way to clean is to sew the line into an old pillow case and then throw into the washer. When finished washing, take out the thread holding the pillow case closed. then loosely coil the lines in large loops and hang to air dry. If the rope is REALLY dirty, detergent and warm water will help significantly. Fabric softener makes the lines soft in the hand, but that might not be needed with docklines.