Did you try a solvent on it? Alcohol, mineral spirits or even acetone might work. Try a small area to see if it removes it but wear rubber gloves and make sure there is good ventilation.

Once you remove it try using the rubber non-skid strip material used in bathtubs. It comes in small rolls about 1 or 1 1/2" wide. I have used it for years and only replaced it once. It works well when you wear rubber beach shoes to keep you from sliding when you are out on the wire.

Howard