Cleaning rust off bedliner bolt heads?

good penetrants are AeroKroil or home made I believe acetone and ATF.

other methods like shock, cold, heat

removal is the sketchy part

rust prevention you could probably take them to a metal shop to be coated in something
The question is whether it’s worth treating the stock bolts that way and downing the truck due to removed

Or not downing the truck and getting spares to treat

I assume any coating won’t be thick enough to alter thread properties

same thing with brake calipers
certain brands zinc coat over their aluminum

I think there’s a well known Porsche resto guy who does that service for calipers. Can probably also do bolts.

 

Now I'm wondering how my slathering of anti-seize is holding up, two years later. Might check 'em out over the weekend just out of curiosity...