In reply to Piers Harley: Yes to the first question and don't know to the second. Will be interested to see peoples experiences of this as I have a couple of ropes that I have considered treating. I would not be surprised to find that it is not as effective as the manufacturers process though.
In reply to Piers Harley:
You can buy Nikwax rope proofing to re proof a rope but I dont think you can emulate factory dry treating which proofs all of the fibres before they are wound into a rope.
Rope proofing doesnt come cheap either. you need a lire per rope (50m)
I have used it but cant say Ive been out in wet enough conditions to notice a difference.
In reply to Piers Harley: most if not all dry treatments have a very similar base and for most if not all to be well bonded to the item they are used on they need some form of heat application like tumble drying. This would obviously not be advised on a rope so I would suggest that a wash in dry treatment would offer very good results when first used but it would wear of quickly and return to it original or near original performance.
I would suggest you pay a bit extra in the future and get a good dry treated rope.
In reply to Joss: not all dry treated ropes have the individual fibres coated mammut for example provide ropes with both types. I've used the nix wax and was fairly impressed but don't expect miracles.