FFS you bunch of skin-flints!!!
When you buy them you clean your screen with the wipes that they give you. Then you fit them and let them run on a dry screen for 10 mins. Then after that, in most levels of rain, you only need your wipers on intermittent. Occassionally you let them run on a clean/dry screen to replenish the coating.
Geddit?
Anyway, those of you that are happy with your cheapo wipers, move on. I have sent Andy a link of where to buy them, so its discussion over!!