I am a new pool owner having just bought a house with a pool. The pool has a concrete water slide the runs from the upper area where the spa is into the pool. The concrete slide has water running down it into the pool. The problem I am having is everyone who tries to slide on the thing gets stuck about half way down. Is there some way I can treat the concrete (it is very smooth) to make it more slippery. Would it help to wax the surface? Would that cause an issue with the pool?