Hokd fire at Eidolon when they go down.
Make sure you lead lures into them first.
This will crack the vomvalysts shells and instantly deposit them into the lures.
You can use this to grab lures too, but do not use it for qc, vomvs will bug out if they break at the same time, and one of them wont go in, this happens commonly with this weapon when using it for qc, or if you shoot through both of them in one shot using a sniper .
Replace tainted with riven if you have one, or electric mod if you aren't using [Volt] Dps or [Shock Trooper].

For concerns regarding how to properly use this, I have a more in detailed guide written in the descirption of this video, along with am example in video of exactly how to do whats stated in the guide: https://youtu.be/Qrh9QIc7jj0