OK so we just had the car MOT'd and he passed with flying colours

except we got an advisory because the headlights are cloudy.
I know there are ways to clean them with sandpaper and various products... but it sounds like a LOT of work and no one wants that, and it's cold and constantly raining at the moment, so I'm wondering... does anyone know a way to clean them so that they're "basically OK" but requires very little time or effort? The latter part is very important to me.
Thanks.