Nothing ever seems text book regarding brake lubes. There have been numerous threads about some vehicle brand brake rubber swelling if one is not exceedingly particular about using a specific product on pins/bushings. Not gonna go there now.
It seems that it is preached to keep petroleum solvent lubes away from brakes entirely. Obviously it can affect the internal caliper seals and other internal rubber components if it makes its way into the fluid exposed areas. But what about the exterior?
3M has a copper anti-seize labeled for brake use. It purports to be water washout resistant and for metal to metal contact areas. Is it better than any other type of anti seize for this application? I don't know. It DOES contain petroleum solvents AND I have seen shops use it not only on exterior exposed parts, but also on the rubber bushed pins. This goes against the preaching to keep petroleum solvents away from brakes.
https://multimedia.3m.com/mws/media/1080858O/3mbrake-jobs-made-better-bulletin.pdf They show silicone for the pins/bushings and the copper for exposed metal to metal areas.
I prefer to use a silicone type brake lube for the pins and a high solids non petroleum product for the water exposed metal to metal areas. Two examples are: Honda(Dow) m77
https://www.walmart.com/ip/Honda-08734-0...13=&veh=sem
or
Pastelub
https://goodson.com/products/bpl-2400-pastelub-brake-lubricant This is a Swiss made product that is impervious to water wash off and I LOVE it. Inexpensive, tenacious, and stops rust excellent. I use it on brake metal to metal areas(pad ears/back) , rotor hats, and hubs. I "think" my high solids pastes are more water washout proof, have less oils to migrate on to unwanted areas, AND leave some boundary lube (marbles) when the oil eventually dissipates.
Yes, use something on the hubs, pad ears, etc. to prevent rust.
Just a paper thin layer. Good luck making your decision.