I can tell you from experience that it is true. Most of the cavities I have had were between my teeth. Because I never did like to floss, and it is so easy to forget.
It has three different modes: Normal, Soft, and Pulse.
Normal is too strong for me, and I recommend you set it to soft the first time you use it. I didn’t even think about that before I turned it on the first time and it actually hurt a little bit. I have sensitive teeth so most of you guys might be fine with the strong. I mostly use the soft setting.
I also made a mess. I ended up with water all over the counters.
After that it was actually fun. Much better than regular floss, and it does get the bits and pieces out from in between your teeth too. And gives your gums a bit of a massage.
There is a big water tank on it that is easy to fill, and it is rechargeable. It comes with the recharging cord, so when necessary just plug it in for a while.
It comes with two nozzles so more than one person can use it. The instructions say to replace the nozzles every 6 months.