I usually drip some thin lube (triflow) on a rag then pull the cable through the lubed rag. Amazing the "blackness" that comes off the cable. I guess the lube is as much a cleaner as a lube, but a thin coat left on the cable before putting it back in the housing doesn't seem to hurt anything. I'll also spray some brake cleaner through the housing (with the cable out), put the cable back through and repeat a couple times. Blow out the excess then the light lube on the cable. Seems to work for me, but just replacing cable and housing when sticky is the best way to get rid of the stiction.