Since I've been driving I've always used
Methylated spirits and never had a squeaky blade in my life.
People changer wiper blades because they smear the screen as they wipe because they think the blade must be worn out. Just put some Methylated spirits on a kitchen roll\towel and wipe the blade rubbers you will see the cloth go black now thats the black coming of the rubber as well as any traffic film the blades have been clearing. Now the black stain will always come of the blades so don't keep cleaning until its clear. Wipe the windscreen glass as well. Methylated spirits is far cheaper than these overpriced glass cleaners and a bottle will last for years.
Oh I forgot to say you don't have to clean them weekly I do mine every couple of months or when it starts to smear again. Plus if you are short of booze you can always have a swig.
