I used to have a rope cleaner that I bought from the shops but after using it once, I lent it to someone and haven't seen it since, but i've got a bit of time on my hands lately so i thought i might try and make my own. This is what I did.

I looked in the dumpsters of building sites and obtained a scrap piece of 50mm pvc pipe. I then went to the $2 shop and bought 3 fingernail brushes.I already had some screws at home(8g, pan head?) you could also use some small nuts and bolts.

When i got home I cut the handles off the nail brushes and cut the pipe to the length of the brushes. I then drilled a hole in each end of the brush, slightly smaller than the screw. I heated the screw up over a candle. and twisted it through the brush hole, thus making a thread for the screw.

Next I drilled some holes in the pipe where i wanted the brushes to go, before attaching the brushes I grinded them down so that they are flush with the start of the bristles. (a sharp screw could cut the rope!)

Thats it. Hope that makes sense. I washed my rope last night and it worked well.