Cleaning is rather complex

Well made, good haptics, no noticeable impact on image quality.
However, I find it difficult to clean it so that neither streaks nor lint, still water spots remain.
I use this a microfiber cloth, of which I dunk a part in a warm, mild detergent solution of distilled water, and that both sides of the filter clean "polish" (wash). Then I pour cold, distilled water through the filter to wash him. Around a little wag until most of the water is gone. But as yet water stains would remain, I polish then coinciding with a super fluffy microfiber cloth until no more water streaks are visible. Then still with a blower blow away a few specks of dust that come quickly after the "polish" with the cloth.
At the right angle held to the light, I can still see light water stains, but I do not see anything in my images and I doubt that one could prove it.
However, it is somewhat time-consuming, and I get it just so down. All other microfiber cloths work even worse, and plain water is not calcareous.