Yeah I'd consider a MOT HV, though. This was an isolation transformer as well, so still not nearly as dangerous as an MOT, but can most likely be lethal is you touch both ends. I was using HV wire that's double insulated so I thought that is enough. I've seen a video somewhere on RU-vid of a guy making arcs with an MOT and holding regular insulated wire with his bare hands, I just thought that was crazy.
Yeah PVC is the best for the money. I used one that was about 1.5 meters in the flyback video just because it's used for other purposes and I didn't want to cut it up. That's overkill, but better to be safe.
