I wonder why they don't salvage flyback transformers from discarded CRT TVs (should be fairly easy to find a lot that still work due to the sheer number) and just use an arc as the UV source. It would also generate ozone, so it would even be dual action sanitation.
Typically, you don't want to create a fire hazard in the course of sterilizing a pathogen that may or may not be present. A bit like cutting off your nose to spite your face.
Air-arc electrodes have fast rates of erosion, combined with the fire issue mean they can only really be used under contant supervision by trained operators in asbestos fire proofed rooms. Which is exactly how they were used in classic cinema projection booths before the advent of the xenon lamp (as well as in other industrial settings).
BTW, flyback transformers do not create high voltage on their own, they require oscillator circuits. So I don't think your suggestion even works economically.