Hi mike, yes the windows i did today were hard work too! (all trad)
Some i had to clean twice for it to be right!
Its just the weather we had last week, the wind was horendous, im guessing these houses were on princes way??
Iv been on highgate westgate and knowsley gate, so these probably were not quite as bad as yours.
Maybe people inland dont realise the severity of this problem,
The whole window and frame can literally be coverered in a hard white salty substance, which when you run your applicator over it, makes such a scraping noise.
I dont think there is an answer other than what you did!! time consuming and a pain in the neck, but this only happens 2/3 times a year.
One idea, maybe hot water would dissolve the salt, you could invest in a hot water system, then when you retire, i could inherit it!!
Just a thought!!