In reply to mc2006:
Caving rope [semi static] is wet most of the time and I'm not aware of anyone using dry treated rope. In fact, I've never seen dry treated semi static...
Soft and pliable rope such as the Geostatic absorbs more water than say Beal Spelenium Gold.
You could try treating your own rope with the Nikwax stuff?
I have 55m of Beal semi static [not the Spelenium Gold stuff, just the'standard' that I would sell if you are interested. Barely used, very clean, never been under ground.