Vinegar is an effective, streak-free, eco-savvy glass cleaner, providing that it's diluted correctly when needed, and that you finish with an important step. Mix one part hot water to one part distilled vinegar. Sponge cleaning: moisten the window, using the solution then clean. squeegee cleaning: always dampen the squeegee first and clean from the top to down, wiping the edge of the squeegee after every stroke