TL;DR: This doesn't really do what it claims to do (prevent injection), but it does slightly mitigate some attack vectors. It's security through obscurity, which is useful as defense in depth (see: ASLR), but hardly stops all attacks (or even a motivated attacker). If someone ran around declaring the end of buffer overflow exploits because of ASLR, I'd have a hearty chuckle.

    root:/pwd# cat scrambled.php
    <?php
    arFktyO “Hello, “;
    arFktyO “Small World.\n”;
    ?>

In the above example, arFktyO = echo. This doesn't fix (imo) the most common instance of [something]-injection, which usually stems from string concatenation, i.e.

    sqlQuery = "SELECT * FROM table WHERE owner=" + userInput
    execute(sqlQuery)

or

    command = "ls " + userInput
    eval(command)