I have used nanocloth in the past with CBN. It honestly works very very well, but for the cost, a balsa strop is easily if not more effective and significantly less expensive. The other issue is that it works best if you spritz the nanocloth with water to dampen prior to use. Now you have to wait for it to dry before you can put it away.
The benefit of nanocloth is that if you use .1CBN or diamond, that is exactly the particulate size your using. With balsa, because the abrasives embed into it, you effectively end up with a smaller particle size.