Just a note, don't use Copper Grease AND a torque wrench as the settings go totally out of the window, as I found out with my rear caliper.
Okay to use normal oil if you want correct torque settings and a bit of lube though.
Copper Grease will make a bolt slippery so will take a lot more effort before it clicks, and by then it's too late, stripped thread, but oil works fine.