I've been to homeopathic/new age shops and they've had them. Tried it out felt amazing on my scalp and head. Totally a non-sexual item, but feels great for a stress reliever. It's also good for dry scalps haha.
I have a non-vibrating one and I just LOVE IT. It's such a cool feeling (like the tingle you get from someone playing with your hair). It makes me absolutely melt, and it only cost me 5 bucks or something.