Water changes IMO
are your best bet. I feel the whole CUC thing is a marketing ploy. You don't really need a CUC as already said.
Now with that said... They are nice to look at and fun to watch. I wouldn't rely on a CUC to keep a tank clean and algae free. Good maintenance schedule, water changes, cleaning the glass, testing parameters, not over feeding, the right light schedule etc... etc... That's the "real" CUC
To answer your question about the NB, I had one and it didn't last all but 2 weeks.