I think he switched to this tool and wire https://www.youtube.com/watch?v=mRc7ZDRcgrQ , but he made the PET strip material popular in the bushcraft community, and from there I think it crossed over to the 3D Printing / Maker community and got picked up for making filament.
Advoko? https://www.youtube.com/watch?v=GSBh77bjz_Q