Maybe it's an oversight that the answer to why Alchemy doesn't have a hireling, they give the example Medicinal Use except it doesn't work. Potion effects that are 10 seconds or 14 seconds with 0/3 Medicinal Use and 3/3 don't change, nor have I seen it work with any other potion type either. I'm just saying its a weird answer to give, that and Snakeblood has no effect either. I'm also guessing the problem is you can't report bug on passives by right clicking it like other abilities or items in the game.