This is a great question and anyone with a leaking pool receiving a quote to repair really wants to believe that this super heap and easy option will provide a solution.
If products like this worked I would not spend as much time as I do jackhammering open concrete decks to repair leaking pipes underneath. Conceptually the product is flawed. Assuming that it WILL seal a leak in a pipe run - and that is a pretty big assumption, the leak is present from a problem with the run. If the ground it settling or the pipe is old and deteriorating -the leak is a growing problem, not a static problem. Any success that you might find with a product like this is undermined by a worsening underlying problem and should be considered a "band-aid" technique.