I used to carry one all the time, and still do occasionally. Nothing could be simpler to use, and they're very effective as an impact weapon on muscle or bone. Getting it off a carabiner is going to be slow. IWB with something hanging from it, like a wrist loop with something on the end is faster. Most comfortable for me is sticking it in my back pocket next to my wallet(doesn't work for pants with real wide back pockets, and hard to get out of slacks, mostly-fine with jeans for me). Doesn't sound secure, but I've had the same kubaton for 15+ years and haven't lost it.
One of my friends made several from aluminum bar stock on his lathe years ago, and grooved them like my over the counter version. Simple to make if you've got a lathe. You could knurl it...