Replace throat 2440 / 2441 in this way?

Has anyone of you made experiences to change a throat in the video shown way?

https://www.youtube.com/watch?v=rMsfvY6F9Gg

We've yet had some discussion about that video some weeks ago and agreed upon that opening the magnetic circuit of an AlNiCo magnet isn't much of a good idea ;).

Best regards!

:D , yes, this guy sells replace throats in bronze, that´s his way to change ...