There is no pain in the worlds of higher frequencies. Therefore consciousness that came from higher worlds are not used to the pain. They know worlds with other laws.
Pain is the attribute of ego. The stronger our ego is the harder we can get hurt. Insulting is always a game of ego. It attacks others to prove that others are weaker or worse. A non-ego based way of self-assertion is expanding own knowledge about yourself and the universe.
I can’t see how insulting can help a person to grow, because by insulting you address his ego and it activates his survival instincts. It’s possible to help if you are not afraid to tell the truth and address higher levels (= send positive energies).