I tried out their product. It’s definitely a scam. Actually, the Canadian government is even advising that you stop using it and ask them for your money back. Here’s a link to the recall notice.
Government of Canada - Healthy Canadians
I had ordered it. Then the same guys called me a couple of months later saying that the device is a fraud and the Canadian government is refunding people for it and they wanted to sell me something that’s really supposed to work. So learn from my mistakes and don’t fall for it. Be wary of any brown guy who calls to sell you anything over the phone. Let anyone else who you know who might be getting calls from the same people know about this.