Bought a product to clean my DE Filter Fingers, it's sold at the pool store as Filter Flush. It has "unique tracer dye", "simplifies use". I suppose this helps when you rinse it to ensure you've rinsed thoroughly. Instructions are to mix 2.5 lbs with 5 gal of water and soak for 12-24 hours. Anyone have experience using this this? The caution label says that it contains Sodium Bisulfate, but that's really the only indicator as to whats in it. Thanks!