The method involves determining temperature of a utilized flushing liquid during pre-cleaning, primary cleaning and final washing with thermal disinfection of an object. The pre-cleaning of the object is performed during a temperature of 15 to 45 degrees centigrade, where the temperature is kept constant for a period of 1 second to 20 minutes. The pre-cleaning is performed with exclusive of softened water. The primary cleaning and the final washing of the object are performed with the softened water or with fully desalinated water.
