Popcorn ceiling is something like vermiculite sprayed up to the ceiling to make those figures looking like popcorn.
The process then calls for spray painting to act like glue to hold it in place and together and up on the wall.
Cleaning????? Normally people do not clean popcorn as it will fall off the ceiling. Most people paint (spray) when its time to clean it.
Now, if your talking about the dust it collects especially around the ceiling HVAC ducts then that is a different matter. I have had good luck with a soft and gentle feather duster. The peaks of the popcorn will collect dust especially around this vent. Normally this is a very good barometer that your filter needs replacing and to go with a pleated and treated filter.
But, other than that, you should consider painting the ceiling other than all over cleaning.
The popcorn will fall and you will have bald spots.