Disclosed is a brush assembly suitable for use in a wet floor cleaning device. The brush assembly comprises a brush that includes a hollow core. An inner surface of the core is compartmentalized into a number of compartments. An outer surface of the core is furnished with brush material, and the core is pierced with a number of outflow openings. The brush assembly further comprises a first fluid injector for injecting a fluid into the core, and a drive mechanism configured for rotating the brush around an axis. Also disclosed is a method for operating the brush assembly.