I came across this video the other day that demonstrates how to create a natural non-stick surface on the grill. It's really simple. Cut a potato in half and rub the flesh on a hot grate of the grill. The starch from the potato creates a non-stick surface.
I gave the method a test with tilapia filets. After the coals were good and hot, I put the grate on top, closed the lid, and let it sit for 10 minutes to heat the grate. Once the grate was hot, I rubbed the flesh of a raw potato on the top left and the flesh of a leftover baked potato on the bottom left. I sprayed the top right with non-stick spray, and I left the bottom right untouched.
When it was time to flip the filets over, I had no trouble lifting the top right piece. The non-stick spray did its job. Where I left the grate completely alone, the fish stuck and some of it stayed stubbornly on the grill.
On the potato-rubbed side, the piece on the bottom where I rubbed leftover baked potato stuck slightly, but the piece that was on top of where I rubbed the raw potato slid right off like the non-stick spray side.
I will definitely try this method again with a raw potato. I would rather use a potato that can be composted after its use than a can of non-stick spray that eventually becomes landfill food.
Now, I just need to figure out what I can create with these grilled tilapia filets!
Here's part 2 of the video, showing that the salmon put on the grill did come off easily.