Hi Delta, I recently bought a house with stippled ceilings throughout (circa 1980 build). I had a structural survey done and during the survey the engineer pointed out that the stippled ceiling would contain asbestos and that if it was ever to be disturbed, that this would have to be considered by the builder handling and disposing of it. I don't know if this is a common occurrence and I don't know if the DIY you are considering would result in exposure of asbestos, if it were there but it just might be something to bear in mind.