Unfortunately when there is a spill of any kind it doesn't just affect the carpet. It also affects the padding underneath. If you don't get the padding cleaned as well, the spot in the padding will surface when stepped on like a sponge. Will keep returning. Some shampoos are very hard to remove and act like a magnet. You just about have to cordon off the area until it is completely dry and that can take a couple of days in a very dry climate.