I have had very good results by keeping a good coat of RainX on the exterior glass. RainX makes glass cleaning much easier and really helps keep the salt shadows (smudges) down as well as the haze you usually get after cleaning with vinegar/windex/etc. Long and short is that it makes glass cleaning a breeze and enables the magnet algae cleaner to slide like butter on the glass. Newspaper works better than paper towels but is more of a headache. Chamois cloths are also too much of a pain, and a silicone squeegee drips too much water on my cabinet and misses spots that later show up as a smudge or salt line. My friends and I all use RainX on our saltwater boat curtains and glass and it really helps keep the salt distortions, streaks, and smudges down.