Other than a squeegee, Ms Morris says "a simple, clean microfibre cloth and some ... "Lukewarm water would generally be the best to use on a window; that way, you'll avoid any cracking or putting ...
Kärcher made the original window vac, and it has now made, in my opinion, the best ... two suction squeegee heads (one 28cm in width, the other 17cm), a squirty bottle for the cleaning solution ...