I posted on Wellness exercise thread. Didn't know about this one. To me it's a waste of money.
I have been exercising for 62 years, and we did these exercises using belts with standing on the floor. We did waist twist, everything with bands and no fitbit cube.
You are right, doesn't look safe and just another gimmick to sell.
They use to sell a wheel that turned to do your waist. So many gimmicks. If a person is really into exercise, they don't need all this stuff. Use your body weight. Bands are good and weights.