My 12 year old son and I spent a few hours yesterday at a seminar learning how to use a kubotan, getting pushed around, and grappling on the floor with a partner. It was great fun!
A Kubotan looks like a fat pen. You attach your keys to it and carry it around with you (but not on a plane, I'm told)! We learned a series of 12 moves and then moved on to practising with a partner. One person would perform an "attack" - for example, grabbing a shoulder - and the other would respond, using the kubotan to make the attacker release their hold or ending with a neckhold, the kubotan pressing nicely into one side of their neck :o)
After a few scenarios, similar to the "attacks" we practise with in Taekwondo classes, we moved on to grappling. Dana Johnson, the instructor at Tempest Taekwondo in Alberta, was our (excellent and humorous) teacher for this seminar. He incorporates Brazilian Jiu Jitsu in his club. We spent a lot of time on the floor, legs wrapped around each other, getting out of holds and applying joint locks to our partners. The woman I was working with was a friend from my usual club and we had a good laugh, though we agreed that it would be a LOT more interesting practising all this grappling with a good-looking man!!!
The kubotan is certainly effective when pressed between the bones on the back of the hand, between the ribs or into the neck. I have a few little round bruises today as well as some really stiff muscles in my neck and shoulders from all the floorwork.