I know people who have done this method on their own without therapy.  However, they do it more slow than described here.  In fact, many therapists go so gradually that the anxiety provoked isn’t horrible as presented here.  However, it describes it well enough.  For scruples, use the same method in religious settings…… or do what your spiritual director instructs!!

https://medicalxpress.com/news/2018-03-tolerance-anxiety-key-ocd-symptom.html