We have just moved into a 17th century cottage. The inglenook fireplaces have beautiful flagstones in the hearth, but one of our cats has sadly urinated on them. I have soaked up the urine, but it has left a very visible stain where it had been. Does anyone have any suggestions on how to remove these stains? I would be hugely grateful. It looks like oil has been spilt and we are devastated 😔