During the 80's and 90's it was really easy to get away with marketing bogus fitness equipment that didn't actually provide any sort of real results and dupe the home audience. There wasn't enough internet penetration in the global market for the real story about real users giving real reviews for these products to get called out so the manufacturers basically all had the same process for selling this sort of crap.
The process was the same on all of them: You hire some models who almost certainly don't use this product at all, have them vouch for the product, show them using it, then make some dubious claims about something like "dynamic resistance training" done by scientists that if they are even real, were likely compensated by the company.
Since the product actually does provide more muscle resistance than sitting on the sofa, the FDA or whatever governing body that is in charge of making sure people don't lie on television for the sake of selling products don't disallow it. Then the masses chalk up $100 for a 1 meter long piece of plastic.
There are many other products like this and the ones that come to mind are the famous "Shake Weight" which uses basically the same concept. If you shake something over and over again the movement of that thing, especially if it has some "give" to it, is going to create resistance and therefore yes, you are going to feel a burn of sorts if you use it for a period of time.
The problem is that two-fold: This movement doesn't cover a wide enough range of motion to actually result in muscle growth and you could accomplish the same thing with a plastic bottle filled halfway up.
Don't believe me? Well go get a milk container out of your fridge and vigorously shake it for 45 seconds with your arms extended. No matter what sort of shape you are in, you are going to feel a burn of sorts. This sensation does NOT mean muscle growth though and it certainly isn't going to be the full-body workout that the manufacturers claim.
in order to try to push the full-body workout experience they feature a bunch of positions that you need to get in in order to work things like your legs and glutes and these are particularly absurd. The only thing that is happening here to activate your lower body at all is that you are consistently setting yourself into an off-balance position and they your body naturally tries to correct this. You would accomplish more by simply doing some squats or planks because at least with that you are going through a full range of motion.
These days it is a lot more difficult for companies to dupe their audience with products like this but believe it or not, the body blade is still for sale today even though it has been well and truly wrecked in the product review department. If you are a true idiot, you can pick one of these up for a mere $70 or so.
In my mind the Body Blade was just another product attempting to dupe the masses into believing that there is a shortcut to fitness that can be done in your living room. I have bad news for these people: There isn't a shortcut and no, you can't do it from your living room. You gotta put in the work and also focus primarily on diet.
I'd like to think that people are smarter today but I doubt that is the case. What I think has happened is that people tend to look at reviews of a product before buying them and even though I am quite certain that the manufacturers try to invade these review sites with fake testimonials, they are easily outweighed by the people who bought it and saw little to no results.
Be smart! Realize that there are no shortcuts and no piece of $100 plastic is going to get you to look like the models in the adverts. Those people lived incredibly disciplined lives in order to look like that and you need to face the fact that there is a better-than-average chance that you never will without the same level of dedication.
I'm nowhere near the sort of shape of the people in the above pictures (except the bottom one because it is me) but I did lose 50 lbs by making gradual and lasting changes in my life... all without expensive gimmicky products. If I can do it, I think many others can as well