Thank you for the reply and recommendation. However, seeing that I am not subsidized with taxpayer money there's no way I can justify government contract pricing. $150+ per ounce is unreasonable for grease. I will check out Dow 33. Any other suggestions are welcome. I'm still wondering if the objective focus ring is really supposed to be run dry, as per what I deduce from the manual.
I did, in fact, try silicone grease and it effectively solved the binding problem, but the result was exactly as you said, it migrates pretty badly.