That's classic. It made me think of changing the oil on a car: Remember to replace the breaker filters, too.
The guy wanted to look competent and if someone didn't know much about electrical work, that might sound like an esoteric piece of information known only to those really experienced few.
I can say from experience it's mighty hard to know you're in over your head and be forced to look a customer in the face and say "I don't know." We've all run into folks who would sooner make up an answer than admit ignorance:
I work with a licensed journeyman who jumped into a conversation between myself and an engineer to "educate" me on how an isolated ground needed to be tied to its own seperate ground rod because the current was returning to earth (one of my favorite myths).
But! In all fairness to the guy who cleaned the bus bars, it seems like I've heard of sparkys gently sanding oxidized/painted bars to improve connection. As long as you weren't grinding off copper...? So, maybe he heard the same thing.
-John
