Before you take the plunge, carefully consider the possible consequences of lubricating rudder cables with PTFE powder. I obtained some teflon directly from Dupont and at the suggestion of one of their chemical engineers, I thoroughly cleaned my cables with MCL. Then made a slurry of teflon powder and isopropol alcohol, coated the cables and let them dry. When inserted into the nylaflow tubing, they and the rudder moved with almost no resistance and I was very proud of my ingenuity.
Fast forward, (I'd be embarrassed to say how long) to final rudder pedal installation. The cables would only move with substantial force, they almost seemed frozen in place. With great difficulty, I managed to pull them out of the nylaflow tubing and they looked as though they were caked in dried cow dung. To make matters even worse, all four nylaflow tubes had this crud over their entire length.
To make a long story short, the cables and tubes are clean and work just fine, buyer beware...

Angier Ames
N4ZQ...soon
N3ZQ...not as soon