You don't need glass cleaner — you need reach

The cleaning aisle holds a bottle for every surface, and glass gets its own. That suggests windows demand something special. For the product itself, they do not.

Dutch consumer authority Milieu Centraal writes that all-purpose cleaners are suitable for cleaning hard surfaces, explicitly naming glass alongside painted wood, tiles and linoleum. The temperature may be low too: for cleaning with all-purpose cleaner you can use cold water, according to Milieu Centraal. And on disposal the authority is reassuring — all-purpose cleaners cause few environmental problems, and wastewater treatment handles them fine.

What does decide the result is technique and order: get the coarse dirt off first with plenty of water, then keep to one direction, and wipe dry before it dries on its own — because streaks form during drying, not during washing. So do not work in full sun or on a warm pane.

Where it really stalls at home is reach. Inside and at ground level you can get everywhere, and window cleaning is a perfectly good job to do yourself. Above that it becomes a question of how far you can extend without shifting your balance, and that is where doing it yourself ends — not at the choice between two bottles. For those windows, the outside on a route costs € 15-35 per visit and inside and outside € 35-70; every rate is in the price index.