As that is a Swyama Siddha Hanuman Mantra it does not have for being chanted for a set range of Mantra Repetitions for being able to use it. Distinctive worship and rituals and policies concerning way, sitting mat, and counting rosary usually are not advised for chanting this Hanuman Mantra. https://www.youtube.com/watch?v=ufkmD95y7fE&t=32s