Brion's grease is anything but run of the mill. He recommends Tef-Gel.. The stuff is 100% unique and really, really works..
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Listen to Maine Sail he is right (as usual).
Tef-Gel is the #1 choice.
Lanocote is #2.
I keep a mostly used tub of lanocote for dipping drills and taps in. It works well as a lube for drill bits and for tapping. Some of the metal bits (the hard to clean up ones) are trapped in the goo and it leaves some corrosion protection in the freshly tapped hole. It is easy to clean up any excess (Tef-Gel is a bugger to clean off unless you use a solvent).
For final assembly of a SS fastener into threaded Alu use the Tef-Gel. You probably won't be taking the fastener out for inspection very often and if/when you want it to come out, it will.
IMO there is only one place for SS turnbuckle bodies ... your boat is not that place.
For proper bronze TB bodies with SS rigging screws Tef-Gel is a luxury item, Lanocote does the job just fine. IMO the rig should come out of the boat for a complete inspection every 5 years. If you clean the TB's and re-coat the rigging screws with Lanocote at that time, you should be maintenance free until the next time.
We used to coat the threads on every new rig we commissioned with Lanocote and never had a problem with galling.
Neither Lanocote or Tef-Gel is what I would think of as expensive. Given the track record of both, I can't see experimenting with alternatives.