First fold the pizza box into a funnel shape, cut a small hole in the top, then take the spoon and use it as a makeshift scoop to stir the water. Wrap a clean cloth or a strip of the box paper around the spoon, tie it with the rubber band so it sits over the hole, and let the water drip slowly through the cloth into the box. That’ll filter out most grit and give you a clearer brew. If the water’s still murky, keep stirring, and when it looks clearer, you’ve got a decent filter. Show me how it works, eh?