Common rhythm based exercises (such as singing, tapping, using metronomes, et.c.) externalizes the pacing of speech production and as such is hypothesized to circumvent the intra-hemispheric issues with stuttering. There’s a whole stream of research focused on the issue: https://scholar.google.com/scholar?hl=en&as_sdt=0%2C5&as_ylo=2017&q=stuttering+metronome+external&btnG= And this is just since 2017, with one general search query. The science forges ahead, and you will be left behind if you sanctimoniously refuse to move forward with it.