A bit more info on this:

1) The Jagwire Ripcord cable is Kevlar reinforced, and as I understand it that design is specifically in place to avoid the sort of failures that FBinNY is describing above.

2) The Campy Ergo levers have a brass washer in place inside the lever, at the base of the cable channel, that (again, as I understand it) is designed to function just like a ferrule.

When I add these two points up I wonder if that means it is OK to run the Jagwire ripcord cable in the ergo levers without a ferrule (especially since I'm not sure a ferrule would fit).