In over 100 interventions, I have never had any easy interventions. They have all had their own difficulties. The most difficult interventions are the ones that are thrown together in an emergency situation and all the facts are not known. Also, there are times when the Afflicted Loved One is suffering from some kind of mental illness that goes beyond the irrationality off addictive thinking - some kind of psychosis, often drug or alcohol induced, or the Afflicted Loved One suffers from a personality disorder, such as a borderline, narcissistic or histrionic personality disorder. These tend to be the most difficult.
The one thing that has helped me the most is to not give up before the client agrees to get help. It may take hours, days or weeks, but as long as I keep going, the Afflicted Loved One will likely relent before me. The secret is to not give up caring, not give up trying, not give up showing the way out.