I am glad to see this topic generated some interest.
After cleaning the outside of the EPs with 100% acetone using q-tips, I realized there was also mold on the inside. Double groan. Although I had no experience doing so, I took apart the EP, which actually just necessitated unscrewing a few components and cleaned the inside with acetone. At one point, I thought I had scrubbed the reticle off (despite being gentle), but this proved unfounded! The acetone left streak marks on the glass, which I then wiped off with an unused cleaning cloth from my Cometron binoculars. This left quite a bit of fuzz on it (I thought it was a lint free cloth-I guess you get what you pay for). I blew the fuzz off with a suction bulb. Finally, I cleaned the outside of the eyepiece with 70% isopropyl alcohol, removing quite a bit of grime.
The 25 mm made it though surgery in good shape. The 12.5 mm, unfortunately, got scratched up some, maybe by the "dust free cloth." My guess it that it will serviceable, if not beautiful. I just need to center the crosshairs on a planet to manually track it at high power and do not care about the quality of the view. I do not think either EP had many/any coatings on the glass as neither had the green shimmering look.
My lessons learned....Prevention is better than cure. Don't put things away wet. I do something different than Martin Pond, even though we live in similar climates. I bring all of my stuff into the house, regardless of the season, and give it ~24 hours to acclimate uncapped, before stowing it away the next day. This includes my OTAs, filters and EPs. My small gear box has desiccant packages but I agree with others that an EP covered by caps then placed in a bolt and THEN placed in a cardboard box, makes it hard to get the water out.
I have always read that cleaning your equipment is a bad idea. I have only had to clean one EP ever before now (my used BZ as it never had an eye guard) although I do occasionally blow the dust off equipment with a suction bulb. I am going to stick with cleaning equipment infrequently going forward. If I ever get an expensive optic really dirty, it is going back to the factory!
My last thought is that the mold or bacteria, whatever it was, is a ubiquitous organism. Prokaryotes can live anywhere, even in nuclear reactors (Deinococcus radiodurans), and I have no doubt that given the wrong/right conditions they can live on glass as a substrate. My guess is as long as your other equipment is clean, they would not easily move to a telescope from the EP. On the other hand, had this equipment not been sanitized, I would have tossed it and started over!
ps: Pictures attached
pps: Televue's advice on cleaning EPs: https://televue.com/...n=Advice&id=103
Edited by kas20amc02, 12 September 2021 - 02:05 PM.