Pulled the cover off last weekend and am ready to go for the season. I have a broom finish concrete deck that is fairly large. This will be our fourth season with the pool. You can really see a dirt line where the cover tie downs were. I was getting ready to clean it with a large brush and concrete cleaner when I saw an ad for a 'water broom'. Has anyone here had any experience with one of these? Are they worth buying? It seems it would make the job easier, but I am concerned that it might not get the concrete clean enough, or, even worse, damage it.