Woody...
That's what I've used to clean up the plexi windows in my dodger. Unless they're pretty far gone, it does a great job of restoring their clearness.
Clean them first with soap and water (DO NOT USE WINDEX, ETC.) and dry them with a soft cloth. Apply the cleaner with a damp sponge and let come to a haze before wiping off with a terry-like cloth. When that's all done, go back over every window with a good grade of wax. Again, hand apply it and rub it off, then buff by hand.
It has also worked extremely well on my hatches and fixed ports.