I did the soothing pat on back and go in (when I felt it was necessary, not by a clock) but with babies who were already used to sleeping in cribs. For me, it was just when they reached the stage when they were showing they could sleep through but just needed reassurance.
Too often I think people Ferberize their kids when they are very far from being at that stage. You can't take a baby who is either scared or upset at something new and leave them to scream for 1/2 hour. It's just going to make him more upset.
I would ditch your doctor's advice. It doesn't work in all cases - kids have to be ready.
What about you laying on the floor while he falls asleep? I did that with one of mine. For whatever reason, she started having problems laying down and going to sleep - so for 2 or 3 nights, I just brought in my blanket, and lay on floor - 10-15 minutes, she was asleep. I just shortened my time and by the third night it was me just sitting in chair until she relaxed. I just read a book - didn't talk to her.
Could you try something like that? It's a big adjustment for some to go from being with you to a crib and separate room.
Good luck :)