I don't spray anything on mine.
Get the grill nice and hot and place the steaks over the fire for about 2 minutes on one side and then turn over and leave for another 2 minutes then move them off of direct flame. This will sear the steak keeping the juices in.
The trick is to not over cook them and never ever use any type of fork to turn them. Always use a set of tongs.
If you have not already marianted them just do this.
Sprinkle with pepper and a little garlic salt. Pour wosterchire on them and let them sit for a while.
Simple and exceptionaly good.