lithium grease is great for steel bearings but over on the classic fly rod forum there's been an in-depth discussion on lubricants. A lot of folks won't use lithium grease on their high end reels claiming the lithium will attack aluminum. I'm no expert but I'd choose to error on the side of caution.
a) it is lithium salt not lithium metal which is added to lithium grease as a thickener ........
b) these salt are either lithium soap ( lithium salt of Stearic acid) or salt of bis-carboxylic acid and they do not react with aluminum
c) for example sodium salt of Stearic acid is what your use to wash your hands (soap)
d) pH of lithium salts mildly basic , water in trout streams is also mildly basic
If you are still afraid , use Yamaha marine grease which has aluminum complex additives.
The ultimate grease is Krytox GPL 207 Grease, which is polyfluorinated earthen mixed with lower molecular weight PTFE ( the same properties as teflon) and has VERY significantly lower wash-out then any other hydrocarbon grease
These materials are compleatly non-toxic and unlike hydrocarbon grease won't be washed out into water. Only b/c it contain fluorine atom , it does not mean it is dangerous. Vinyl chloride monomer itself is toxic !!!!!!!. When polymerized produces PVC used as a coating on fly lines ..........
Krytox is far more stable and exceptionally resistant to harsh environment including very strong cid and bases then any other existing grease. It is not use everywhere due to coast and a small quantities like 0.5 to 2 oz acost in $ 20-30 range
Nothing will beat Krytox
Super Lube is simple hydrocarbon grease with small amount of PTFE. The issue is fluorinated materials are not soluble in hydrocarbons, and consequently there is grease/oil separation.
Anyone who use SuperLube has noticed it.
In Krytox, PTFE ( pure PTFE is solid) is perfectly soluble is oil ( polyfluorinated either) and consequently there is no oil/solid separation.
It is well known that in some classic reels with Van Hoffe open drag often trace of hydrocarbon lubricant gets washed to Derlin shoe/stainless drum and reel can hydroplane when wet.
Pure PTFE grease wan't be washed out at all. Many times had large fresh fish on my Teno 4" ( fresh Skeena Steel or an accidental Chinock) and the reel never hydroplaned !!!!