Some coffee spilled on our carpet quite a while ago- we soaked it up as much as possible, and cleaned the carpet with our steam cleaner. But lately it seems to be coming back. Seems like everytime we try to clean it, it just brings more up from the padding or something and looks as bad as ever. Since it is in the middle of the floor, pulling it up and doing something about the padding is not an option- Any ideas? Any 'home remedies' for this?