IMO:  stick with a microfiber, dry.  I think someone mentioned using a "fresh" microfiber, but I would wash it first (and only microfibers by themselves, no fabric softener whatsoever, and no dryer; air-dry).  
IF** removing the dust is not good enough, then I would go towards either distilled water and/or the highest % of isopropyl you can get.  Only very lightly damped.  
I've also used an automotive type of electrostatic brush.  It works well, I think.
Do not over-clean.  The best is to not use any chemicals or water at all, unless absolutely necessary.  Well, this is what I know about cleaning PJ lenses.  (I once received bad advice here about cleaning my PJ lens, and I won't mention names; I'll just say I've never once followed his advice since.)  Hence, don't go overkill, and just dust for now, as that is usually the only thing that happens (outside of kids).