I assumed this product was some kind of detergent. A detergent (or more precisely a surfactant) breaks water surface tension and binds dirt/oil/scrum molecules to water molecules. So the stuff you're trying to clean off is removed from surfaces and held in suspension within the water to be drained and rinsed away.
This product did the exact opposite. It took something (presumably oil/film/gunk) that was suspended in the water and deposited it on all surfaces. It didn't get gunk out of my plumbing, it put gunk into my plumbing where I can't clean it off. At least I can clean off the shell and the outside of the jets. I removed the jets. They were previously clean inside before using the product. Now they have spots of green goo inside that I can't reach, and I can see it in the plumbing behind the jets too. There's also at least one jet that was flowing fine before using the product that's now weak. And the green has the tint of copper oxide, so I hope this stuff wasn't eating away the inside of my heater. EDIT: On second thought, iron oxide is more likely. Perhaps a heavier than usual dose of metal remover will help get rid of the stuff I can't reach.
If that's what it's supposed to do, then it seems like a totally pointless and counter-productive product. Why would you use such a thing?
To answer your questions, we usually shock weekly, clean filters monthly, and change the water after 3-6 months depending on how much we're using it and water quality. We'll go through periods where we use it about 3 times per week, and then it's usually time for a water change after 3 months. We'll go through other periods where we use it once a week or less, and will change the water after 6 months. Our spa doesn't have a blower, but I did open the air valves per the product's instructions.
