What is the best way to prolong the life of a fibre glass pole? I have heard suggested rubbing baby oil, silicone spray or a non-wax based polish onto pole helps it wear better.
For most of my work I use 18 x 3 foot universal fglass pole.
The best way of prolonging the life of a pole is to keep it clean. This means flushing the pole from the inside out so that all the grit that gets carried up on the pole hose is flushed away and doesn't act like sandpaper between the clamp and the section. In an ideal world, you would flush your pole after every day's work.
To do this, lean the back of the brush head on the ground, undo all the clamps and point a standard garden hose inside the base cap and allow the water flow to flush out all the grit and muck from between the sections out of the clamps. Once you've done this, turn the pole the other way up and spray as much water as you can in the top section and in between each clamp and allow the water to flow out the bottom of the pole.
Even if you could only do this once a week, it could double the life of your pole.