You'll get mixed answers on this. My take is you have a crystal clear pool and have left phosphates out of the equation. Why fix something that isn't broken? What will you gain?

If you follow the directions properly and use a commercial grade product (no PhosFree!) then it should work similarly to an algaecide. That's a somewhat high level though, your pool will get extremely cloudy after treatment and you will need to get all of it filtered out before closing. It could clog up your DE filter so you will want to be able to babysit it for a day or so. As Dave said though, there are differing opinions on how well it would actually help and whether it might be easier to just clear up the green in the spring. It's entirely possible you go to the trouble of reducing your level and still open to the same thing next year as this year. If you do decide to do it though we would appreciate an update when you open as to whether you think it helped or not. It's certainly not a process you will see being recommended here any time soon, but having more information on others' experiences is invaluable to the overall knowledge base of TFP.

Well, I guess I thought the getting rid of algae food would increase my chance of not opening to a green mess.