There is no blanket rule that locs should never be washed. Scalp hygiene matters, and washing frequency should reflect oil, sweat, activity, product use, environment, and scalp condition.
Starter locs may unravel more easily, so technique and timing may need to be adapted. Established locs can generally tolerate a routine built around the wearer's scalp needs.
Rinse thoroughly and dry thoroughly. The objective is a clean scalp and locs without excessive manipulation or prolonged dampness.