I've got something like kool deck on our pool decking. The past couple of years I've power washed it. It takes forever. I think the guy who sprayed it told me to use muriatic acid at 1 part to 10 parts water. I've been hesitant to mess with that because of handling the acid (I'm a chick). Should I just suck it up and do it? I know the power washing is hard on the surface.