In the paper, they sealed the material in a quartz ampuole under vacuum.

I wouldn't call it an easy process, but it's achievable without highly specialized equipment. Just a torch and a vacuum pump.

There's a surprising number of them around. I think the bottleneck for quick repro will be mat sci people, not equipment.

> need a furnace that can hold a vacuum

Here you go: https://www.youtube.com/watch?v=icniCydn_kE

Those are easy to make.