Cover Popcorn Ceiling What Is The Quickest, Easiest Way To Cover Water Stains On A Popcorn Ceiling W/o Repainting The Whole Thing??

What is the quickest, easiest way to cover water stains on a popcorn ceiling w/o repainting the whole thing?? - cover popcorn ceiling

I am old water stains on the ceiling, which is very "Popcorn". I WILL NOT paint the thing, as I sell the house. I think I need to use Kilz or spots to break again. Can I paint with Kilz? What use is the best way - brush, cloth, sponge? Thank you!