If it's only dust that you're trying to clean off, last time we cleaned our lenses we used a microfiber cloth (those are awesome) and canned compressed air. We got those lights very clean.
Sorry for the delayed response - we use some coated lenses (anti-reflective), some uncoated lenses, and coated glass reflectors in Source Four fixtures - the alchohol/water advice in the current manuals is what we can suggest for all of the different glass bits in our fixture products. It provides a one-size-fits-all cleaning method and it is based on the latest information we have from our lens/reflector providers. I think that some of the other methods discussed earlier in this thread will work just fine, but we have to go with the glass guys' recommendation. I'm often tempted to soak a reflector and a lens in blue Windex for a month or two to see if it actually tints the glass. I've wondered myself if that could really happen.
ETClens I wouldn't, but Century I'm currently working on... Jet Dry and dish washer in getter done and good enough. School type industrial dish washer.. worked a week or two at boot camp with such a thing, (I cannot remember honestly my experience at any point in time with it) this much less months at a pizza place in washing their pans - such washers would be great for lenses. My latest 8" Century Fresnellens is headed to the dish washer as with perhaps the reflector for it.
