Of course you can also just draw a black rectangle shape over the sprite to 'remove' it, but thos is really not a good thing to do, sibce you should call clear() ever frame iteration, because you don't fully 'own' the video memory that's used for showing stuff on tze screen, but you have to share it with other applications. So if you don't clear it you'll get some strange noise.
There's a complete pong gane being shipped with the SDK.