Before talking about the swabs themselves, I should point out that the EF 70-200/2.8L IS USM does not contain any fluorite elements. Instead, it has four UD glass elements.


Now, the problem here is that you are using a product not specifically intended for cleaning optical equipment. The issue here is that you don't know what exactly is in the solvent--for example, if there are any impurities in the alcohol. More importantly, however, is that you do not know if the swab material itself is designed to be non-abrasive on the coatings.


The truth of the matter is that all techniques for lens cleaning, except for one*, slowly degrade the coating over time. Any time you are rubbing something across the surface, you are rubbing away the coating on a molecular level. You'd have to clean the lens pretty obsessively over a period of years, and even then, all you do is send it in for a front/rear element replacement (if the lens is still serviceable). In truth you'd have to seriously damage the front element before you might even notice it showing up in any of your photos. So people will use non-specific methods to clean their lenses and not observe any damage and then conclude that their method is fine.


*From what I heard, the one method that is safe is the use of non-flexible collodion. I've never tried it but I have heard that this is how reflex mirrors are cleaned. It seems tedious and requires a good deal of practice.