From the Haggadah of the Roshei Yeshiva, pp. 103-104:
אחד רשע / a wicked one
Sometimes it happens that a man has a wicked son. The Torah tells us that this child must also be treated as a son. The Torah also gives advice as to how this son should be dealt with: Blunt his teeth; that is, respond to him with the same harsh tone that he used. There are many guidelines for dealing with this child, but are exhorted not to completely disenfranchise the wicked children among us.
R' Chaim Shmulevitz illustrated this idea with several actual cases, using the admissions policy of a yeshivah as an example.
Sometimes, when a boy seeks admission to a yeshivah, problems arise. They notice that the child has a personality problem -- he does not act nicely, he lacks manners, etc. There is a precedent for such a case in the Torah, R' Chaim said. Timna, the Gemara (Sanhedrin 99b) tells us, was the daughter of a king, and she sought to convert to the Jewish religion and throw her lot in with the Avos... The Gemara is telling us that whatever the justification of the patriarchs, they should not have rejected her so completely... The Gemara is telling us that the patriarchs were taken to task for not finding some way to accept Timna into their ranks despite her shortcomings. In an instance like this, the yeshivah should accept the student.
Often a child presents a somewhat different problem: In addition to his own shortcomings, the student will have a negative influence upon others in the school. Although this is definitely a serious consideration, there is a precedent for exhibiting sensitivity in this case as well... Avraham did not encourage Lot to leave his presence just because his own spiritual life was being hampered, but only when he began to be a menace to the broader community, when "there was a quarrel between Avraham's shepherd's and Lot's shepherds" (Bereishis 17:7)... It was only when Lot's behavior became injurious towards others that Avraham decided that it was time for him to ask Lot to depart from him. Nevertheless, Avraham was taken to task for sending Lot off: The Midrash (Bereishis Rabbah 41:11) tells us that God disapproved of his course of action, saying, "He becomes friendly to all people, yet to his own relative he is not friendly!" this, too, is not a reason to alienate. One must merely find the proper way to develop a relationship.
Another problem occasionally met with when deciding whether to accept an applicant into a yeshivah is an academic consideration. The boy's level is not sufficiently high; he will not understand the classes. Here too there is a precedent. The Gemara (Sotah 47a) tells us that the Nazarene (the founder of Christianity) was a student of R' Yehoshua ben Perachyah... This student misunderstood his rabbi's comment about their hostess; he did not comprehend that it was totally inconsistent with his rabbi's level of sanctity to make a comment about a woman's appearance. He was obviously not on the level to understand the rabbi's teachings. Yet the Gemara criticizes R' Yehoshua for unrelentingly pushing the Nazarene away... [On the identification of the protagonists, see this post - GS]
Another problem that often arises is that the new student may disrupt the yeshivah's program or sow seeds of dissent. These are such terrible acts that, in describing the malice of Geichazi, Elisha's attendant, the Sages consider them equal to idolatry (Sotah 47a)... Despite this, Elisha was taken to task for distancing Geichazi "with both hands"... No matter what, absolute alienation should not be the approach.
We must indeed rebuke the wicked son, or, as the Haggadah puts it, "blunt his teeth." Yet it is equally important to remember the lessons discussed above, and to take care not to renounce the rebellious child entirely. For he, too, is a child; a child of Hashem.