What do you use to lubricate a noisy speedometer cable?

The speedo cable in my 1974 Duster rattles when its cold. Sounds a bit better when warmed up. How do you lube the cable core? Pull it all the way out of the housing? Maybe then clean it up really well, then lubricate before running the core back into the housing? Whaddya think? What's the best lube for this? Dry graphite or something else? Thanks- cruiser