There is literature out there that does support the Camperdown Program. However, it will require a lot of practice on your part. Sydney Uni actually provides a wealth of resources regarding the Camperdown Program, even the 'levels' of technique use, the program guide, and videos of what the 'technique' sounds like at first (before you start making it sound more natural): http://sydney.edu.au/health-sciences/asrc/downloads/ As for whether it is useful, it really depends on whether or not you think you'll be comfortable using the technique (there are examples on the site I linked), how much you are willing to practise, and your speech pathologist.