He may mean either but to answer your question on Nioxin, I use it every day regardless of any cycling. I don't have MPB nor does it appear to run in my family. I had a hair stylist years ago tell me how great the stuff was for hair in general, even though it is marketed for guys with thinning hair. All the research I have done on it shows that it does remove DHT from the scalp and create a more friendly environment for hair to remain, but doesn't seem to be as aggressive in doing that as some other shampoos/scrips etc.. I have run test and used Nioxin one day and then Nizoral the next day (alternating I mean) and didn't notice any difference in my hair loss at all.
I just like it in general, it's just a nice little benefit it may help keep my hair even if just in a small way. If you have hair issues, have you looked at Finastride?