I usually spread a bag of new stone dust in the cracks after a good cleaning. (eileenandersonrealtor.com)
In a 1998 study, less than 8 % had developed stones again within a 4 year period (although a few cats developed new stones on multiple subsequent occasions). (2ndchance.info)
It is important to detect new stones while they are still small enough to pass. (marvistavet.com)