I'm repairing old Nikkor-S 50/1.4, it's first time I'm working with helicoids. I cleaned it all up, I even managed to get rid of all the fungus. I bought some graphite grease for the helicoid, but it was too damp, o I've decided to clean it all again and I reassembled it without grease for now. But the focus ring is still kinda hard to turn, compared to my Nikkor-S 35/2.8. Is there a grease that would loosen it up even more than it is now, without a grease?