Combo brake and derailleur cables???

I just looked at a set of Jagwire Rattler Mac cables/housing. The housings look as though they have
a woven wire cover, but I can't tell if it is real or not. This housing/cable set said it was
specifically for mech. disk brakes, but the inner structure of the housing looked to be longitudinal
wires, rather than a wound wire. Isn't that derailleur cable housing? Is it possible for the housing
to do double duty like that? I have noticed, in my searches around the 'Net, that some cheaper
places have combo cable/housing set-ups, but Jagwire?

Now, for the meat of the question - if someone with an 8-sp. MTB rear der put one of these guys on,
would it work? (I have seen Jagwire Rattler Mac der cable/housing advertised...)

Thanks,

Spider