Does Rain-ex damage wipers?

Rain-X, like any chemical that sticks around, has a residual film which can attract dust and debris. When you used your wipers on this chemical it allowed everything that has been accumulating on your wiper blades to clump up and cause poor performance. The alcohol you cleaned them with dried the rubber up severely, so it may be too late for those blades now.

Only one trick I've ever learned can restore a blade once it gets dried out (as long as it's not not dry-rotted). Use some car wax (preferably a hydrophobic polymer blend synthetic wax) and wax the windshield same as you would the car. Once the wax dries, buff it off and immediately turn your wipers on so the finest layer of the remaining wax will coat the blades and smooth them out. It also doesn't hurt to spray a little water on there while they're wiping. Rubbing a small amount of non-greasy leather conditioner on the blades couldn't hurt either.

In normal circumstances, you only need to wet an old wash rag and, lifting each blade up, grab and squeeze just the rubber blade itself and swipe all the way across it. Look at the rag now. It most likely left a black streak on it. If so, repeat with a clean portion of the rag until it wipes clean.

In my experience, the quality of the blades depends on the quality of the rubber or Teflon from which they are made. A softer material removes water better but catches debris better too. Repeat that cleansing trick every few months to keep them working like new.

Tip: If you do end up having to replace them this time, try to find TRICO NEOFORMS. They're the only ones I've ever dealt with that will hold up to literally anything, because instead of traditional rubber they use patented Dupont brand Teflon. I personally haven't found any blade that will outperform or outlast them - even the more expensive can't compete.

They're around the same price as you're BOSCH Icons were. You'll also notice that waxing your windshield works better at beading rain away than Rain-X ever could. The Rain-X anti-fog formula is the only one I'd even consider using, and only because it goes on the inside of the windows.

Your windshield was not cleaned properly before applying the Rain-X Original. Your wipers are perfectly fine, there’s lingering dirt and grime on your windshield, it’s hardly ever the wipers unless they’re torn. The RainX in the tall spray bottle is crap, you want the RainX in the little 3.5oz cardboard box. It’s just better somehow. Now You need to deep clean your windshield to remove all dirt and debris that glass cleaner won’t remove. You need RainX Xtreme clean and a pack of new microfiber towels. Walmart sells all this for really cheap. You really need to scrub at the window for awhile until the glass feels slick and smooth when rubbing the XtremeClean on the glass. The glass should not feel rough in spots, if it does, scrub more. Deep clean with Xtreme clean and then spray SprayWay glass cleaner on it and clean the windshield. Do tiny bursts with the glass cleaner on the windshield and use a new dry towel to buff until streak less. You can stop here if you don’t want any hazing when the wipers swoosh back and fourth. Then get the rain x and a microfiber APPLICATOR PAD (the pad is important) and wipe the rain x on in HORIZONTAL MOTIONS, do not move the pad up or down when wiping or it will make the wipers streak if you apply in up and down motions. Wipe horizontally one way, then bring it back, pick up the pad, move down, rinse and repeat. Your wipers will not streak or chatter this way. Then let it haze slightly and pour water from the top of the windshield and let it drip down, then get a new microfiber and do the same horizontal motion like you did to apply the rain x to remove the water and the rain x. Presto! You’re done! Thank me later :)