Make Me Clean by Tina Baker

Maria is a good woman and a good cleaner. She cleans for Elsie, the funny old bird who's losing her marbles, with the terrible husband. She cleans for Brian, the sweet man with the terrible boss. She cleans for the mysterious Mr Balogan with the terrible neighbours. But if you're thinking of hiring her, you should probably know that Maria might have killed the terrible husband, the terrible boss and the terrible neighbours. She may also have murdered the man she loved. She didn't set out to kill anyone, of course, but her clients have hired her to clean up their lives, and she takes her job seriously - not to mention how much happier they all are now. The trouble is, murder can't be washed out. You can only sweep it under the carpet and pray no one looks too closely...