Polyfilla will give you the best result but it's going to take a long time by the sound of it. However, if you do decide to do it that way make sure that you put a light by the wall to highlight all the blemishes otherwise you'll miss some until you start to put the paint on (or normally when you've finished, are sitting down and put a table lamp on.)
I've used polyfilla in the past (I too have a dry lined house). You need to leave it ever so slightly proud when applying and then lightly rub with fine sandpaper once dry. I've found that if you smooth it over with a palette knife you will make the finish too smooth and it will show once painted.