So, quick lesson on PTFE tape, for anyone who's not a plumber:
Pipe threads are (generally) tapered, and seal by a tapered male tightening into a tapered female fitting. But, because threads have a small flat at their crest, and a small radius at their root, the seal is not perfect... there is a "spiral leak path" in all tapered threads (excepting specialty NPTF, etc.). PTFE tape is designed to fill this spiral leak path, as well as providing a lubricant that helps prevent galling as the tapered fittings are drawn tight.
But PTFE tape should not be used on any other type fitting, most of which rely on an O-ring, flat rubber washer, compression ring, or flare to seal. In all of these fittings, the thread is NOT part of the seal, but rather just providing the mechanical clamping force to the o-ring, flat washer, compression ring or flare seat.
The fitting shown in the video appears to be an o-ring fitting, meaning tape will not help with, and in fact it likely to interfere with the actual sealing of the fitting. If she found it helped, then it's either because the O-ring was missing, damaged, or the o-ring seat was damaged.
You should be applying a silicone-based o-ring lube to these o-rings and threads,
every single time you remove and re-install them. This provides lube to the threads, to prevent galling or snapping during removal, but also lubes the o-ring to prevent tearing, and to allow more tensile force per torque (same reason torque spec's on bolts go down when lubed).
One tube will last most people 20 years:
If that woman found the PTFE tape helped her in any way, this is likely via lubrication. If she was not lubing the fitting with o-ring lube, then the dry fitting probably couldn't be tightened properly. Adding PTFE tape does help lube, albeit with other problems, but that may be helping her get more pressure (tensile) on the o-ring for a given applied torque.
Also, store your plugs out of sun for winter. Few things embrittle plastic like UV exposure!