Since I have two refractors, I was looking for the right cleaning agent for the lenses. After discussing the issue with Al Nagler at TeleVue, I found that the best stuff to use is "regent grade acetone". The material will clean lenses and mirrors without leaving residue. Apparently, reagent grade acetone is different than the stuff one buys in the store because it is pure.
So off to the internet with a search for some. I found a chemical company in New Jersey and bought a "gallon"!! The deal is that the gallon was $30, but getting it here cost another $30 (because it's flamable).
Anyway, if anyone would like to get some of this, and make a "donation" to offset the cost, I'd be glad to share..
If you'd like, contact me off-list at dsteele at email dot com.
Thanks, Dennis