I just give them a light coat of spray paint. I DO NOT try to remove any oil or clean them in any way. Coil a dozen of them together, spray one side a camo color, flip them over spray a different camo color on the other side, then strip each side with a third camo color. You can do 100 dozen with three cans of paint easy. Do not try to cover them completely or you can impede the lock's speed. A little cable showing through is fine. You can go set them as soon as they are dry. Once uncoiled, they are near impossible to see in most every terrain.
Or, just dip them as is in Formula 1 brown, when they dry go set them...