Speedo cable replacement?

Just Curious! Are you changing the cable because of a problem?? If So, 9 out of 10 times the problem is in the Speedometer itself. I Love this Dupont stuff that sprays into a cable like a liquid then conforms to grease. It's called Teflon Multi-use Dry Wax lubricant. I shoot some into the cable and it gets rid of Squeeks and binding etc...