> that depicted a couple officers locking their phones into a grounded metal box - a faraday cage

I once tried that using a metal lunchbox, with a tight fitting metal lid - the phone rang anyway.

Anyone else ever tried it?

And as a side note, be sure and turn off (or airplane mode) your phone if you do put it in an effective faraday cage, or you will rapidly drain the battery as the phone constantly tries - at full power - to find a base station.