hi ive had this problem you can get carpet sprays for when your cat dog etc peees on carpet they seem to kill the bacteria from milk thus kills smells its the bacteria which grows after milk that causes the smell. id first wash sponge over carpet and under it clean water then let it dry then spray stuff spray it regular and it will go. also i tried shake and vac on car carpet after that gives car good smell. better than those trees by the way i can smell that car burning from here