What prevents forgers from generating such magnetic fields? That might be worth while if people start to blindly believing that "pottery frozen magnetic fields are not possible to counterfeit". Note that "not possible to counterfeit" is not a claim in the article.

The method of seems to involve hearing the artifacts which seems plausibly risky for an ancient artifact.

can this clue be circumvented by using magnets oriented in a certain way around the workshop while constructing the pottery?