Acid Sprayers are designed to kill Zenith ships. They work best against all Zenith fleets, where they take minimal damage; just get in close and tear it up. A very niche ship though.
I was really struggling against a Zenith Descendant, then I found these guys when I capped an ARS. Made life much easier. They do take a while to kill electric bombers though, but take little damage in the process. Last time I took Acid Sprayers against a Zenith EB wave it took a good while to kill them all, but I took no losses.