It worked incredibly well. The word "jay" is a slur used to refer to "country bumpkins" or out-of-town idiots. They paid actors to spread the slur and even staged mock funerals until their newly made up slur spread and people started calling each other that.

All of this led to the 1928 Model Municipal Traffic Ordinance and notably a lot of laws in LA that shifted the liability to pedestrians instead of motorists.

Today if you "jaywalk" in most of the country you get called an asshole. It was an incredibly successful act of social engineering