When Jack's boss angrily finger-wagged him into his office, Jack knew he had done something wrong. There we saw Juquinha's angry boss finger-wagging him for repeated tardiness. Later that day his boss fired him. Please stop finger-wagging. Do some finger-licking for a change.
Here in Brazil it's very common to finger-wag when turning down an offer. However, it may sound a bit heavy or even rude to Americans, since they feel like being reprimanded or lectured for what they've done.