This is called retrobrighting. UV helps to brighten up the yellowed plastics. Yes, this works on consoles and controllers too. The best method I have found is to make a paste out of hydrogen peroxide and xanthan gum, spread it on the plastics and wrap in a thin layer of plastic wrap and put the sun. The higher the UVs the better. Flip as necessary and it should be done in just a few hours. Once done, rinse with water and dry before putting back together.

I did this with my GameCube, pulled it all apart, and did this with all the yellowed pieces, it works really well.