Soot on glass is easy as compared to soot on brick or paint or wood. White vinegar and dishwashing detergent and warm water will help. I would use microfiber rags as they tend to pick up more than you expect. I don't know if those window squeeges would work but grab one from the dollar store (along with the microfiber rags, etc.) to see if it works better than the rags. If the firest are not yet gone from your part of the world, you'll have to do it again. What a task! I'm glad your house didn't get touched by the flames!
Be careful using a pressure washer if you're thinking of doing that. Your window frames might get compromised from the pressure.