If I do that will my rating go down or does it not recognize the players?
Play yourself

There are times when playing an opponent that he misses the best move which I had anticipated and prepared for. It is nice to see the continuation.

Once in an over the board practice game I played the moves for myself and my opponent, who had much less experience playing chess than me, and I ended up losing!
I often play with myself, but never to much, because you could go blind after all.
It starts Slowly The Blindness

I have had a number of opponents all of the sudden just stop moving pieces and they let the clock run down (typically in losing positions) . I am fairly certain that is exactly what they are doing - playing with themselves.

Play "against" is impossible, for some. They will get in a position and begin to "pull" for one side. Play with yourself to learn is one way to put it, and more realistic. I will set up the board in a random way, legal or not legal positions and begin from there. Lessening the tendency to pick sides.
I never tried it, but is it possible to play against yourself?