Care of Jagwire shift cable housing?
I've done a google search of bikeforums on this topic but can't find the specific answer to my question so here goes.
I just got a used 2001 Giant TCR2 that came with Jagwire shift cable housing and a 9-speed 105 group. It looks like the bike hasn't seen a drop of lube since it was purchased. When I turn the handlebars or wiggle the cable housing near where it exists the STI levers there's a nice crunchy sound coming from it. Shifting works OK, but if I adjust the rear derailleur for crisp downshifts (to larger cogs), the upshifts (to larger cogs) become sluggish. This looks like a classic case of gunk in the shift cables and clearly the cables need to be cleaned or replaced. However, I don't know if this Jagwire cable should be treated the same as Shimano SIS cable or if it needs special treatment.
My first thought was to get the gunk out with WD-40 or a citrus degreaser solution, but what do I do after that? I've read that greasing shift cable housing is bad because they are "self-lubricating" and the viscosity of the grease just makes shifting more sluggish (especially later if dirt gets inside). Some people suggest a light lube, but not oil. Would a dry lube with Teflon work OK?