Isopropyl alcohol is safe to use on optical glass with or without multispectral/antireflective coatings. I'd stay away from the pre-soaked swabs, though, unless they are specifically for optical lenses. For example, this Zeiss lens cleaner is pure isopropyl alcohol (100%, as opposed to the 70% isopropyl alcohol you find in a drug store). Note that for salt (e.g. dried spray from the ocean), distilled water is appropriate - alcohol is intended for removing oil-based residue, e.g. fingerprints.


That should really be all you'd ever need. There are stronger solvents that are also safe for use on multicoated lenses, but they're overkill for cleaning camera lenses. For example, the Zeiss cleaning fluid that I use on my 'other' lenses (to remove immersion oil from microscope objectives that cost more than theEF 800mm f/5.6 L IS USM) is made from a petroleum distillate one fraction lighter (more volatile) than aviation fuel.