I think it only took two days of usingLitter Getter to get my cats to use all the litter boxes I have. I also have an automated litter box that two of my cats would not use and I have had it over six months. I mixed the Litter Getter into my bucket of cat litter and mixed it up and put the litter in all four of my litter boxes. After a day I didn't really see any thing but on the second day I caught one of my cats using the automated litter box and I had never seen her using it before.