Internal cleaning of brake cable outer

laurentian

The rear brake pull on my Wilier has got a bit "notchy".

I can replace the cable and the rearmost outer (the one that goes to the caliper) but am reluctant to replace the outer that goes from lever to frame as it is routed beneath the bar tape and looks very neat and tidy (which it undoubtedly wouldn't if I unwrapped and replaced the tape in order to replace this cable outer).

I am hoping to remove the cable and somehow clean and "refresh" the inside of the cable outer that goes from lever to frame.

Anybody got any ideas how I can:

a) Clean the inside of the cable outer (initially I thought something like a pipecleaner with some kind of solvent on it)
b) What (and how) to apply some protective coating (oil?) to the inside of the outer to eek out a few more months/years use before I have to bite the bullet and remove tape etc.
c) Are there any suggestions as to the best coating to put on the new brake cable? The length of cable that runs under the top tube between bosses is housed in a small diameter plastic outer (I guess this is the same as that which they run through on internally routed cables)

Any help appreciated

First.Aspect

The old cable will make a nice pipe cleaner for any detitus in there (if, for example, you used PTFE coated cables, urgh). Other than that, get the straw end of a WD40 bottle and flush it through.

MattFalle

Basically as above but I'd use GT85 as it smells nicer.