You may want to consider a multi-coated UV filter from Heliopan. They're not inexpensive, but you never need to clean the surface of the scope lens itself.
The less you need to clean a lens/filter surface, the better.
In rain or snow, blot off water with a tissue, or similar.
For cleaning, you can use a lens brush to remove larger particles from and around the lens/filter surface.
It's possible to remove all remaining grit with a Kinetronics Anti-Static Canned Air Ionizer, clipped to a Dust-Off (or similar) compressed gas duster.
Purosol lens cleaner (applied with a Q-tip, or similar) removes smudges without streaking. Residual Oil Remover takes care of remaining, difficult greasy spots.
Pec Pads are non-abrasive, non-reusable cleaning wipes.
Off-topic, but a LensPen FogKlear Dry Anti-Fog Cloth works nicely on a clean lens/filter in high humidity.
A kit of this stuff lasts a very long time.
Mike