AIO is a strong paint cleaner. Use it whenever you want to remove everything off the paint and start over. That may be twice a year or it may be once a year. It depends on what you are doing with your car.
I use it once in the spring as part of my spring cleaning. I might use it again in the summer before a car show when I want all my products to be as fresh as possible. Then I'll usually use it in the winter as part of the winter prep work that I do.