Plague Bearer help

[Hosscatt]

I have smashed the goo jar in another level against a wall and no achievement popped. Is there something in particular I need to smash it on? (Luckily it had multiplied in my janitors chest so I have more).

[A JANITOR]

take 1 to caduceus and smash it on a full body depends which map got goo jars from if got them from caduceus smash one on a full body in evil science then body goes all green infected