Right on, I would be highly skeptical about running them myself. And Iv never actually heard of anyone doing it, other than that one HT article at least 18 yrs ago.
You would need a actual spectragraph(?) to determine if it even put out any light a nm range MJ can use. then way pros vers cons. Keep in mind there are a few different types of blacklights. some are nothing more than painted glass. And without looking it up, i believe real ones have a certain make up of phosphors and such to produce the violet colored light.