I recently inherited a integral fitted washing machine when I moved house and discovered that it had a very bad smell and some of my washing was coming out with a brown sludge on it (lovely....). over the past few weeks I have tried using soda crystals and other washing cleaners set on the hottest wash, but the smell kept coming back after I completed subsequent washes, as did the brown sludge on some wash loads. I got Afresh cleaner tablets and did 3 separate washes one straight after the other as advised on the instructions for a badly gummed up machine. So far it seems to have worked, I have completed more washes in the machine and it has stayed smelling fresh rather than the smell creeping back as previously. I would rate these as a worthwhile buy.