Thank you. Saw a tip in the paper last week, in an article about preparing cars for winter. "If your wipers are squeaky/ineffective", it said, "clean them with a rag soaked in dilute methylated spirits or vinigar". After cleaning the screan and wipers with white vinigar, I can report that they work perfectly and silently. No more squeak, judder or missed areas.
I always use white vinegar and clean off with newspaper, both inside and out and stops the smearing/fogging better than any glass cleaning stuff I have tried