But even if you never need to use it I can see where you might get the idea that you need it. I use filter every day and I still am not sure how the code is supposed to work, except that it must be an object. So this is a way to see the object in your mind or it is a way to see it in your head if youre still confused.
I wrote a piece of code that uses php filter to do the same thing. That piece of code is about three times as long as mine, but it does a lot of the same things. I used it in a function I wrote to change the color of a div on the page, and I have to say it was a lot more efficient than my original method. I am still learning php filter, but I think you can use it to do a similar thing.