I don't know if it's the best filter cleaner but you'll find that several people on this forum do use it with good results. IIRC, they say that it works best to run your filter through a couple of dishwasher cycles to get all of the chemicals out. Since I don't have a dishwasher, I've never used Simple Green. You could probably just spend 10-15 minutes rinsing with the garden hose. Just rinse a lot more than you think you need to, or you will have the foaming problem.
Take Care,
Gil