The first research nurse will undertake wound cleansing for experimental group. Wound cleansing in control group is done as usual by the staff nurses in the four designated clinics, who will attend an education programme which explains the details of the study, the procedures to be followed, and the patient documentation. The first research nurse and the clinic nurse who undertakes dressing change are responsible for the ongoing assessment of the wound during cleansing and recording the information on the volume of solution and amount of cleansing materials used, frequency of dressing changes and the type of dressing applied at each visit. Participants are instructed to report any signs of infection to the first research nurse and the clinic nurse or physician. The second research nurse who is blinded to the wound cleansing method will undertake data collection and wound assessment for all subjects at enrollment and upon healing of the wound or at the end of six-week period if the wounds have not yet healed. Wounds that have not healed at the end of the six-week period will be reassessed and data relating to the wound characteristics are recorded.