Lens manufacturers say that anything other than a microfiber cloth will damage the coatings on a lens. But microfiber cloths eventually pick up crap and they look like they're a pain to wash.
How do you keep your lenses clean? Are you using cloth/kleenex or microfiber cloths? If you use microfiber cloths, how do you clean those?
Odd. I've tried the Zeiss spray+microfiber cloth before, and it just didn't work for me. It leaves greasy smudges on my lenses. I've found that only dish soap or the Zeiss disposable wipes actually left a clear and clean lens. Are you using Zeiss spray or a different lens cleaner?