I don't think your going to find many if any here who use kuji in of any kind, at least none who actually know what they are talking about. You might find the random ninja wanabe here claiming to use them but i have yet to see anyone discuss them that have any real knowledge of them. The furyu article you linked pretty much says it all in reference to their use in the martial arts. They really aren't even taught in the legit modern ninjutsu systems anymore with the exception of maybe the Genbukan and To Shin Do.
Enjoy life while you can, you never know when things will change.