TSP....or just do a primer coat of KILZ.
Linda C

What Linda said. If you cleaned and painted and the stains re-appeared, you probably need to do a Kilz coat and repaint. I've never tried TSP on painted walls, but if that works without removing the paint -- that would work for future stains after the walls were primed and repainted. I would also recommend Charlie's soap to get at those grease spots before they become problem.

I use good ol amonia with a few drops of dawn dish soap. The two together work very well and there is very little scrubbing. This works on windows as well as wood surfaces too. Hope this helps.