I JUST replaced my inserts. Bought 24" silicone rubber inserts from Amazon for $4.99 each with free shipping (Prime member). They make them in 28" too. Carefully pulled out the old inserts, removed the two steel stiffeners from each old wiper (the new wipers are molded and look just like the old ones, so there's slots for the stiffeners) and than reinserted them in the new wipers with tape wrapped around them to hold them in place for a few seconds until I inserted them into the J clamps on each arm up to the tape, removed the tape, continued until the prongs snapped into place.
So for $10, had a new set of wipers for my Winnie. Without wasting the entire metal arm. At that price, I can afford to replace them every year...but since I've used these before, doubt that will be necessary.
Here's the link to the inserts:
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1