I've come across two ways to secure php includes:
1 - With a lock and key code ($ping = "pong" and $ping != "pong")
2 - by placing the includes above the root directory and accessing them by absolute path (include "/path/to/includes/myinclude.php";.

Are these viable? Or, am I wasting my time trying to secure my includes?

I'm asking because some of those includes contain ad code.