Personally, I'd rather see someone using 3 scoops from a 9mm case than someone using a real measure and knowingly using triple the amount of recommended charge (their charges were actually pretty light for a .45 cal rifle). If the dipper works for now, why spend $10 on a measure that's going to sit in a box for 5 or more years? If you're going to shoot a lot, then by all means get the requisite possibles.
These guys weren't doing anything dangerous IMHO (except to their ears I guess). Not smart, but not dangerous either. And, they admitted in several places that BP snobs would come out of the woodwork to give them grief. These guys obviously don't spend much time shooting black powder. They weren't after accuracy. They just wanted to have fun.