Sounds violent, but of course it isn't. You are just exaggerating your motions a bit, in a way D clearly understands and responds to.
I am teaching this maneuver using the diagrams below, and after the students do it it a few times, it improves their performance. It feels graceful, like a dance, and makes the run more fluid.
No flatwork needed. It is so intuitive for D that when they see both your arms outstretched together, and you inscribing an arc, they just follow it. It's a very powerful signal. It is intuitive enough for H that it only takes a few times to master, and once practiced a bit, everyone's performance becomes more fluid.
Upwards and onward,