Oh ya, I hum to keep my conscious mind occupied rather than using the mantra. But when I first started it was essential for me to use it. When beginning the course the mantra totally helps especially when Paul takes you through the photofocus process on tape 3.
As I have gotten used to the process I have found that I can adapt the system to make it work for me. I know what a good photoreading session feels like and anything that induces those states is perfectly acceptable.