In reply to alex_frost33:
When ever I have washed a rope, it's not handled the same afterwards.
Exactly how dirty is it? Does the dirt actually matter?
If it's been battered, maybe buy a new one? Or at least prepare yourself for the possibility that you may be buying a new one.
When I climbed lots, I had a succession of ropes. The good new ones for outside, the older ones for redpointing sport routes, the older ones with bits chopped off the ends for indoors and then the remains for setting up abs, top ropes and hammocks, tow ropes etc etc
Although I've had dirty hands from my sport ropes, I think the issue is more the belay device leaving residue through wear than the rope picking up real dirt.
Trad ropes don't seem to get dirty or stiff in quite the same way. They get warn out or just replaced due to age generally.
Not so helpful with the soap flakes, but I'd probably just buy new ropes if they were that bad