For my previous car, i had the brakes liberally lubricated only during brake changes. I never had any problems with this method. I have a friendly garage who does the brake wear and rotor wear checks because the dealer will always let you know or somewhat "scare" you into changing them prematurely. They tell you over the phone that they also do brake inspection "for free", but they wont just hoist up your car and not make money off of it once you're there; someone has to pay for those dealer lights, couches, air conditioning etc .

But since they do tire rotation, oil changes, and clean the battery terminal, then i suppose it's worth it.
To my knowledge, that brake lubricant is nothing more than brake anti-squeal,
correct? so if your brakes were not squealing the first time you came in, that means they had enough lubricant to last, supposedly until they needed to be changed, assuming your brake pads, rotors, shoes were not worn out.
someone correct me if i'm wrong.