Yes restoration is easy on an old fiberglass ladder..
Step 1. Take your sawzall out of its compartment.
Step 2. Install your favorite brand of demolition blade. I personally like a fine metal blade as it feels so good.
Step 3. Cut that &itch at every rung straight across.
Step 4. Pitch all the remnants in the garbage.
Step 5. Go to your favorite outlet, home improvement, wherever and get/order a new ladder.
See? In 5 easy steps that hairy fiberglass ladder is completely restored! Good for another 5-10 years of service with outdoor storage use. I've destroyed many ladders at my day job due to the fiberglass delaminating (that's what yours is doing btw) it's not worth risking getting halfway up and the fawking thing breaking in half and killing you. I've seen my guys cringe when I see their ladder is getting fuzzy because they know it's dead then and there. I have literally thrown them off the truck rack and cut them up, ran them over with the forklift, bashed them with a backhoe, whatever I have handy I will kill that ladder before it kills somebody.
The reason I'm like that is due to a ladder I let go for too long and I got to take a ride I'll never take again! Sorry man but just get a new one.
For those saying to keep it out of the sunlight, yes you should. But if you work out of a service truck in the service industry, that's something that just don't happen. The ladder lives on the truck along with the rest of your tools/**** because if it's not there you will surely need to get up on a roof, so that means you have to drive BACK to where the ladder is stored out of the sunlight. Which means wasted fuel, wasted time, and the job isn't getting done. Or you can just buy a new ladder every few years and get lots of work done because you didn't fiddle fart about your ladder/other tools.