I'm with Campy on this one, if you are going to lube use powdered graphite for your lube. Anything else can "gum up" with age.

As for the plastic inserts on the control rod. Those are spacers that are there to keep the control rod from flexing inside of the pushrod tube. Without them you can have anywhere from 1/16" upwards to 1/4" of flex in a control rod. This makes for at best weak control surface that have lack of authority when flying. And at worst they can be a cause of flutter in your control surface which can destroy and aircraft in a matter of seconds.

Hope this helps

Ken