The Yeshiva Neve Tzion in Telstone (near Yerushalayim) has a quite remarkable group of Rabbeim who work with kids way off the derech. I personally know 5 boys that went there and all became Erliche Yidden.
They make no secret of how they succeed: They truly love the boys. They constantly daven for them and weep for them. I know from personal experience of their deep love for these boys.
(the point I was originally planning to make here, I decided not to make. I think I’ll send the post anyway)