No, this is about the EM field. The magnetic field of CRTs is very weak (so weak that it is dwarfed by nearby rail power lines which have a rather weak M field

No, this is about the EM field. The magnetic field of CRTs is very weak (so weak that it is dwarfed by nearby rail power lines which have a rather weak M field as well; so weak that you have to recalibrate for monitor movement relative to earth's M field). I doubt this works, at all, for a variety of reasons.