And if it starts to dry a little, we wet it again just before we squeegee it off. Tool number two is a black rubber squeegee. Dry a narrow path on top and then dry the squeegee and start the second pass in the dry area. Every drop you put on has to come back off, or you're leaving dirt on the window. The third tools are blue hospital towels, which are very absorbent, lint free and reusable.
Terrycloth is a good second choice.
And for serious dirt, use a giant flexible razor blade made in Denmark. Always make sure that the blade has soapy water for lubricant, and that the window is wet with soapy water as well. And the window is wet with soapy water as well. A dry blade will scratch the window. If you want the cleaner that the pros use, you can find it at any janitorial supply store.