As this is the Swyama Siddha Hanuman Mantra it doesn't have to get chanted for a hard and fast number of Mantra Repetitions for having the ability to utilize it. Unique worship and rituals and policies relating to course, sitting mat, and counting rosary are usually not encouraged for chanting https://www.youtube.com/watch?v=ufkmD95y7fE&t=32s