i said it would break because i tried it before and it broke. the lead stuck on the gear and i had to open the drive and clean it.
i don't think pencil refill is always handy. most friends i visited in the past a few year did not have any pencil at home.
you talked about the technique in using the pencil refill and mentioned about how to keep it from breaking. Even if it doesn't break, it will leave at least some lead which will degrade the gear.
When a more convenient solution is available, why do you still want to waste time and take the risk by going the harder way?