Helping one’s fellow to improve his charcter also falls within the realm of toeles, constructive purpose. If an acquaintance requires character refinement, then the mitzvah to reprove one’s fellow Jew requires one to bring the matter to that person’s attention with care and sensitivity. However, if one feels incapable of offering reproof and knows that others are also aware of this person’s character deficiencies, he is permitted to discuss the matter with them and seek their advice or involvement, if necessary. Though we have seen that it is lowly and forbidden to speak negatively of someone even with those who are already aware of the information, constructive speech is not at all lowly.
Should one find it necessary to consult with someone who is unaware of this person’s deficiencies for guidance in how to approach the person, he may do so, for this too constitutes constructive speech. However, if it is possible to discuss the issue without mentioning names, then this course must be followed.
We have already seen that if one seeks the active involvement of someone who is unaware of the situation, that individual would have to investigate the matter personally and verify the facts before taking definitive action.
Sefer Chofetz Chaim, 29 Cheshvan, pge 166