Torn roots wont kill plants, but if the plant cant take up water it will die. If u tore almost all the roots off and the plant is drooping then the leaves need some trimming and the plant needs to be placed into a cup of water (like a rose in a vase) so all branches firm up and stop drooping. Replace the water with fresh water twice daily until roots start again.
If u still have a good amount of root left, and no drooping leaves u are all good.
The plant naturally produces anything that the rooting solute will contain so I dont recommend wasting cash on that snake oil.