How do you clean acoustic sprayed ceilings?

You can not clean them in a conventional manner. You could vacuum or sweep cobwebs and such off them but putting water on them causes the material to get soft and come off if rubbed or scraped. Sprayed ceilings can be painted over using a roller. Many people have an aversion to the look of sprayed ceilings and want to remove the spray to get a smooth ceiling. This can be accomplished if the ceiing has not been painted. Wetting the ceiling with a garden sprayer and scraping the material off is a very messy process. If you choose to do this put plastic on the walls and floors. The ceiling will need additional float work with sheetrock joint compound and sanding.