Sam Longley's method to protect and clean his boat's halyards over the winter
All ropes that can be easily removed I take home over winter, but the halyards have to be left aboard. So I attach redundant cordage to the ends and hoist them up the mast, meaning that lengths that were exposed to the elements are now hidden in the mast. The length that normally spends its life up the mast, laying on the deck or soaked in salt water when the sails are hoisted can now be coiled and washed in a bucket of fresh water then hung to dry.
Once dry, I coil the ropes and put them in a couple of thick black bags, which keeps out UV and maintains dryness. By tying the bags to the mast with the open end downwards, any water that may enter the bag soon runs out.