Both medication and psychotherapy especially ERP will help him recover out of OCD YOU can call on me to take the psychotherapy.

Both medication and therapy together have shown maximum results and chance of symptoms coming back after stopping medication are more if you are not doing therapy Second there many different therapy available not just cbt , like relaxation, mindfulness, psychoanalysis, psychodynamic therapy etc Third if it is ocd , then review the dasage of medication with the psychiatrist

Yes therapy is important with medications & will help him to manage his OCD symptoms in a better way. I would suggest your brother to take psychotherapy from a Psychologist.