Just tamed two on official. I built a small 2x6 box with a Dino gateway out of stone. Park my Dino nearby, then swim with flippers to gain aggro. Kited 4 into box, and i escaped through doorframes. 2 somehow got out through a hole in the ceiling before i could patch it. After a death and some shit, it's was super easy to feed them biotoxin without getting shocked. The stone walls protect you fully. I don't see an easier way if you build your own right.

More Electrophorus Taming & KO Tips