@susie
You don't need a squeegee. Use newspaper or microfiber cloths/towels, one to which you apply the cleaner and one to dry them. Basic cotton dishrags shed lint and leave streaks more easily. On the topic of streaks, avoid letting the cleaner on the windows in sunny weather as that will leave streaks. Check if your windows lever inside to clean them.
Don't risk leaning out of your windows.