Your friendly neighborhood optician says: "Use NOTHING but a clean, high quality microfiber cloth." The O bag don't cut it. Neither does cotton, wool, silk, nor any paper product." Although, if you *really* like your local optician/ski shop guy...you can always use any of the above...especially the bag O gives you...and your local retailer will be thrilled to sell you replacement lens after replacement lens!
I can't begin to tell you the number of O lenses I've seen destroyed over the years that were "cleaned" using just the bag. The only thing they truly seem to do well is clean away any hope of clear, scratch free vision.
I love the spin they try to use on their "iridium" lenses. They're the same low cost mirror coating that any number of other mfrs use. Nothing special in any way shape or form. In fact - them stating that you can't clean them with a cleaned should be enough to make any reasonably savvy man run. Any well made lens will be made to be cleaned with any decent lens cleaner.
On a side note - NEVER use ANY form of AMMONIA based solution such as Winded. It will kill just about any optical lens. Save it for your house windows, and keep it (and any overspray) away from glasses and goggles alike!!!