Don't buy those expensive cleaning for routine cleaning of lenses. If you look at the Material Safety Data Sheets ( which everything under the sun has one, for it is required by law in the US) for cleaning solutions such as Leica and other brands. You will find the main ingredient in just about all of them is Isopropyl Alcohol (rubbing alcohol).
For years I cleaned lenses doing the following.
1. Blow the lens free of any dirt and sand.
2. Clean with 91%> Rubbing Alcohol.
3. Wipe with Distilled Water to remove any streaks, this step makes coated lenses come out looking like the day it came out of the box.