Lens Cleaning

Was looking for a Fish eye angle lens ( Sigma 15mm and Nikon 16mm ) last Saturday, and when I noticed there was some imperfections on the lens coating, they took to it with a blower thing-y. They could not get it off, so as a "last resort" they took to it with a cotton bud with lens cleaner, and tried to clean it that way.

But they refused to use a lens cloth !

Can anyone tell me the correct way to clean lens ? Obviously the lens shop dont like physical contact with it

Not to make light of your problem, but this is a pretty funny web page:

http://www.cameraquest.com/lenscln.htm

Seriously, I have heard of a lens-cleaner product that Nikon and Kodak are selling. I haven't used it, but I imagine that if Nikon markets it, it must be effective, or at least safe.

http://www.wisementrading.com/optics/lens_cleaners.htm

Thanks for your help. The Nikon 16mm fish eye I would classify as a serious lens, but what about the coating. Will it scratch ?. We all spend tons of money on lenses, and proper care is I think of essence to maintain their quality

Any more views ?