After heavy mud or sand use. Pull out the length of rope that was used plus 5 feet. Use two 5 gallon buckets of clean water (or more buckets if needed). Soak the used portion (or a portion of the rope -depending on how much was used) in one of the buckets. Let sit for approx. 10 minutes or so (depending on how muddy the winch rope is). Agitate the rope to loosen the mud and/or sand from the fibers. Remove approx. 2-3 feet of the rope from the soaking bucket and put it in the second bucket of clean water and agitate again working the remaining mud and/or sand out of the rope (this step may need to be repeated in a third bucket of clean water). Remove and lay on the ground (preferably grass). Repeat the process until the winch rope is clean. The winch rope does not have to be dry in order to respooled on the winch drum.
If the winch rope was used in dry dusty conditions, it is possible to just use a garden hose to rinse off the winch rope. Keep approximately 3-4 feet from the winch rope when rinsing. DO NOT USE A PRESSURE WASHER TO CLEAN YOUR SYNTHETIC WINCH ROPE!!! DAMAGE TO THE WINCH ROPE MAY OCCUR.
Use a winch cover to protect the winch rope as much as possible from harmful UV rays. Although your winch rope has a coating to protect against UV rays, it will still fade and shorten its lifespan.