if you are doing insides then you need trad tools and skills.
Whatever kind of water you use, if you are using a squeegee and applicator then you will need a detergent of some kind in the water, whether it is pure or otherwise.
When you use WFP outside there is a continuous flow of water and most soiling on windows is water soluble.
On inside cleaning there are other contaminants, cigarette smoke and so on that need a little more than water to break down and clean properly.
Trying to squeegee off a window without detergent in the water is awful!!
For smaller panes, use an atomiser and pure water, but add a drop of GG3 or any other specialist liquid, lightly (very lightly!) mist the glass and buff dry with a microfibre or scrim (I personally think Microfibre is WAY superior to scrim).
Or buy a cheap spray bottle that already has a window cleaning solution in it. Tesco's own brand window cleaner is excellent by the way..and very cheap.
Another way is to buy a 5 litre container of windscreen washer liquid, very cheap to buy and will last you forever, you only need a capfull at most in an atomiser.
Or, a method I often use is to lightly dampen a clean Microfibre cloth with pure water, on georgian windows, if you are on a repeat clean then you can, if you have have the Microfibre just barely damp, get away with cleaning with just that...
Though that is a very real skill that takes some developing, better to use a damp cloth and polish off with a clean dry cloth.
And as has been said, you could simply put the pure water in an atomizer and not put in something to breakdown any grease you might come across, simply mist & buff dry.
On relatively clean glass on repeat cleans this would be all that's needed.
IF you are WFP, then the water in your tank is going to be water that's softer than a baby's bum, so you need only use GG3, as GG4 if for hard water.
Ian
