Well, RailClone surface tools are a little limited at the moment. Rather than follow the polygons or the UVs like a paneling tool, in RailClone, geometry is projected along the RC object's local Z axis until it hits the surface's geometry. This means that it only works well when the face normal points towards the RC object. Any polys with faces that point away or overlap will not work well and sadly that's the problem here. You could perhaps get around it by spitting the surface and using several RC objects with different orientations but I don't think it would be easy, or even possible to get them to align so that it looked like a seamless rope structure. Another option might be to use Forest in the UV Surface mode, but it would have to be very accurately unwrapped (and you'd lose the deformation if that's something you're looking for).