A better - easier way would be to go into the fuse panel and pull the fuse for the electric fuel pump.
It would crank, but without fuel it would never start. Without fuel, any attempts to start the engine would not flood it.
Look in your owners manual. It will tell you which fuse. They are usually marked Fuel or F/P, etc.
However, disabling the engine will not prevent it from being towed. If the thief wants it bad enough, not much will stop them.
