We have been asked to clean a very slippery driveway (again). It has algae and mold all over it. We used a Clorox and water mix last time along with a product from Lowe's that said it killed driveway mold. We mixed it in with the Clorox too. We scrubbed the driveway good with brushes but.....now a month later the mold is growing back. Does the chemicals in Clorox just evaporate in the air? And...then are they "gone"? OR if the Clorox dries on the driveway, and then it rains, do the chemicals come back? We were going to spray a stronger Clorox and water mix on the driveway and let it dry. Some will sink into the cracks of the pavement = that is the problem. It is a black top porous surface and just scrubbing it will not get the roots of the mold down in the cracks. We were thinking that if we pour a Clorox and water mix on there......being careful to keep it on the driveway and not in the bushes.....then it will drip into the cracks and kill the mold? And we would do this on a dry day when it can dry. But.....when it rains...will the chemicals get "re hydrated" and run off into the bushes? Thank you if anyone knows.