This is in Japanese but you can figure it out from the photos.
There's so much easy comedy there that I'm not going to bother. I'll treat it seriously: on one hand it looks somewhat safe, in that if anything goes wrong, the toy portion of it is going to fall off. There is no firm physical connection between you and it.
On the other hand, even if it works, it looks like you could end up with friction burns. That's one of the last parts of my body that I want burned. One day I was cutting up chili peppers and got it on my hands, which eventually got there, and I thought that was hellish enough.