Rolling textured ceilings
Found the information, but it is not what you want to hear. A few of the manufacturers strongly recommend against painting a popcorn ceiling. Apparently paint seals the surface and diminishes its ability to hide smoke and dirt. This in fact is the purpose for the pores in the surface.
However they do recommend spot cleaning with bleach and water or they all sell chemicals for the cleaning. They also sell repair kits. Here is a name of a company that you can write to if you wish. You can explain your situation. I have written to them in the past and they were very helpful. You will need to enclose a self addressed stamped envelope for the reply. Also ask for their free brochure on how to care and repair- its free.
Sprayed Textures Unlimited
1518 Hwy. 138
Wall Township, NJ 07719
Sorry I couldn't be more helpful. Maybe if I stay off the site for awhile others will answer more........