I just hit my tank with it and and it works.
I removed as many as I could get and after dosing continued removing them as they started coming out from crevices and floating into the water column. I would recommend getting them at first site and not waiting as it will decrease the toxins they release (the fewer the worms the better). It has been over 2 hrs and I see no signs of stress on anything. I have the carbon running to clear the chemical as well as the toxins. It worked so well that in 30 seconds they started floating.