I was finally able to hunt down Core Distribution Inc. which handles Xtend & Climb. I left a message late Friday afternoon and they called me back Saturday morning (I was impressed!). She sent me the following information on maintaining telescoping ladders and said this applies to all telescoping ladders, not just Xtend & Climb.
That’s what I used and didn’t have a problem…wipe them down after use once in a while and extend and re-apply silicone…maybe once every 2 months or so…is what I did.