I would use your fingers not leather.Take your tube of wax and slide it up and down on the string, then take your fingers and briskly slide them up and down on your string and cables and work the wax into the fibers.Then take a paper towel and wipe off the excess wax.This serves two purposes, it conditions the string and cables and will "HELP" keep moisture out of the fibers which can make them stretch.Hope this helps..Good Hunting