Greetings,
Seems there are a few ways to go about cleaning the lenses. Most important is what is comfortable for you, and works the best. I have not had good luck with the micro-fiber cloth method. The Q-tip, after I fix any loose threads, works best for me. Have tried regular glasses cleaner, but that did not remove all the dirt. Also tried laser disc cleaner and was about the same. The Q-tip with 91% alcohol method works best for me. Never thought about vinegar as a cleaning fluid though. It is good for regular glass and not leaving streaks, so as long as it doesn't hurt the AR coating I guess that would be ok.
Definitely need to use some kind of lens cover, or even better when not in use keep your laser in a case. I found out the hard way just leaving the aperture exposed it will pick up dust and debris. Especially if you smoke.
cheers,
Moe