one night our one cat, gray, snuck into the house and stayed during the night. she has a terrible habit of peeing in our floor register of our living room. it smells terrible and we can't get the smell out. but now, because gray did this, our house cat, baby, is now peeing in the register.. who knows how much. all we know is that it's getting worse. no matter how much we try to get the smell out.. it just gets worse. please help!! it smells so bad.