Honestly, just use fire.
A molten magma facial does wonders.
(Also, I should point out that a sword, especially the kind depicted, IS NOT SHARP. It is more a crushing weapon with a tiny surface area. The hair is more likely to get pulled out during the attempt than it is to actually get cut. Hair is actually pretty sturdy stuff in the aggregate. In order to do what is depicted, that sword would have to be sharpened first, which is actually BAD for the blade. Now, if that were a katana or something, that would be another story, but no-- that thing is someplace between a longsword and a bastard sword.)
The article you linked isn't that related to your claim, it's just talking about uniformity of sword sharpness. It doesn't say that most swords are dull (which, though a popular notion with nineteenth century historians, is not a claim actually borne up by surviving examples) but only that those intended to encounter armor are comparatively duller at the tip than along the length.
As for the blade in the comic, it's quite clearly a jian. Even if you were expecting a slightly heftier guard, that's not nearly universal in real life examples. It also should usually have some taper to the blade, but mostly distal taper, which wouldn't be clear to see given the angles and the art. The tip is also not a usual shape for older specimens but every other element is a classic example of the form, and the blade as a whole looks very much like something from the Ming period. I'm not sure why you went to an expert in European blades in the first place given, you know, the hanzi.
More to the point, a jian could be quite sharp. A European sword from Clements' primary range of study period would be around chisel sharp for a good portion of the length, (which I reckon is theoretically possible to cut hair with even though very difficult, making it a possibility given that this is a trial) but a jian very well might approach razor sharp, especially at the tip. Considering that these these practitioners follow the path of cutting, not the path of bashing armor, I think their swords are likely sharper, at least for those non-masters who even still need a physical sword in the first place.