How do I clean popcorn ceilings?

Hello Barb! Cleaning popcorn ceilings is just no fun! Some of the popcorn will fall off as you clean but usually there's still enough left up there that you won't notice! If you repaint your ceiling less popcorn will come off when you clean later. https://www.wikihow.com/Clean-a-Popcorn-Ceiling

I use a microfiber duster that "grabs" or a use my ceiling fan brush.

Gk's note re: painting is true but if you ever decide to remove it, painting will make that task much more difficult.

Vacuumed them with a brush attachment

Vacuum or paint it. It will continue to fall off every time you try to "dust" it. A cloth will pull more pieces off and the fibers will stick to the ceiling. Popcorn ceilings are made of small pieces of Styrofoam or vermiculite that is blown. Others are in the form or tiles. The fact that it is not one piece of material, it will continue to crumble every time you try to dust it. If you don't want it to continue to crumble, wet it and remove it with a scraper or paint it. the layer of paint will help the pieces to stay put.