Make:

Curtis writes "One of my biggest climbing challenges off the rock is cleaning my rope. Between the oxidation off carabiners and the rope being spooled into the dirt for belays it has grown a filth over the years that covers my hands with just a few minutes use. I've tried a couple techniques like using 5-gallon buckets of water, putting the rope inside pillow cases in the washing machine, and just trying to not use it too much. Nothing really works though and I was mentioning it to friends when one suggested "they make a device that attaches to a garden hose and washes it that way." So I decided to make my own. I made two of these washers for less than $8 in parts (not counting the glue which I had anyway.)" - Link.