In research, when we plan a field design for eventual community transfer, we are trying to be simple. Literature shows that 1) between 1 vs. 2 brushings, a large difference of effect but between 2 vs. 3, this is small difference of effect; 2) Natural and average frequency of daily brushing across different type of patients, tends to be 2x/day; 3) So, in all designs including instruction about daily frequency of brushing, was 2. This is without completed challenges such higher frequency to keep, such specific method of rinsing, etc.