I agree with all after "Rant Over !" Blocked is a short, sharp word understood by all, and therefore useful on a busy freq. It's actually been around for decades, so I am surprised at the sudden interest. The alternatives mentioned seem perfectly reasonable, if longer.
The advent of Contran has certainly reduced the incidence of cross-transmissions but unfortunately is by no means a universal fit. No doubt it will eventually become mandatory only after another tragedy, just like CVR, FDR, SSR, GPWS, etc, etc.