There is no "cure" and any therapy for stuttering is something that is learned and practiced for a lifetime.
Your best source for information and help for stuttering is the non-profit Stuttering Foundation of America.
After any therapy session, a person who stutters will be more fluent because they learned techniques to help their speech. The Stuttering Foundation of America has a list of summer and intensive clinics as well as referrals to speech therapists who specialize in working with those who stutter.