Reading some comments and articles concerning the situation I believe the most practical way would be to fly another drone and ram it out of the sky.
Ready a cage drone like this;
Cover it with some sticky gum adhesive that can cling on by contact and ram it against the intruding drone.
The intruding drones will try to gain control but you only need to force it out of the air so just pull the levers to go straight down.
If you want to be creative, arm the Kamikaze drone with sticky adhesive spray and spray it on the intruding drone's rotors.
It may not stop it but is sure is going to make it difficult for the drone to maintain balance making it easier to ground it.