does anyone know how to clean high-up sash windows?

[mamateur]

We're on the third floor and have big sash windows. The top half has been painted in, so I can only raise the bottom ones up. Does anyone know of a good kit so I can get to the outside?

Has anyone tried this??

We used to live in a flat which had similar windows. They were cleaned either by jetwashing by a man with a van which would be parked in a road, or by a window cleaner climbing out of hte window and harnessing himself to something while he did the outsides. I couldn't bear to watch. Sorry.