I would be leery of any weapon as short as a knife that was electrified along its entire length. Any canny character who saw such a weapon (and still wanted to fight) would do their best to grapple you so that if you hit them, you would both take half the voltage.
Also, who would design this weapon? Is this a one-off, or custom piece? What is the market for this weapon? Will a lot of people buy it? How would it be marketed as anything other than a weapon of complete cruelty that would annihilate the reputation of any company that put it on the market as anything other than a gag weapon?
I thought about this, and here's what I came up with:
-Extra shocking mechanism in case they survive your first stab
(anyone who can survive your first stab and still fight back is probably not going to be put off by an additional shock) = lawsuit
-Good for taking down trolls/critters
(maybe, if it weren't so inhumane) = lawsuit
-A humane knife that does massive tissue damage, but also cauterizes the wound
(maybe, except electricity burns inside out, and leaves wounds highly susceptible to infection. Often, you would be sealing contaminants in the wound) = lawsuit
I would probably allow it as a custom weapon, made by a truly sadistic Humanis armorer.