Screw the water sprayer with a mist setting option onto the end of the hose. Set the water sprayer to mist so that the water distribution is light and airy. Light distribution of water to dampen the concrete walls will prevent damage that a heavy water flow would cause.
Spray the concrete walls with the water sprayer. Fully dampen all sides of each concrete wall. Do not wet the walls too much or you will change the concrete-to-water ratio. Doing so could cause the wall to weaken and lead to cracking.
Repeat the dampening process every day for one week after the concrete wall was set.