If the porcelain floor tiles were not pre treated, I would use a protector just as this one from Fila. Being porcelain, they are very hard wearing, but can sometimes soak up fluids that can leave a stain. This protector can prevent this. I also use the other products from Fila such as Grout Cleaner and Natural Stone Sealer. All are available from Topps Tiles.
Here is the floor tiles almost all laid. Everywhere excluding the wetroom shower floor has been covered with a beautiful 60x30cm mat black porcelain tile which has been pre-treated during manufacturing from Porcelanosa. Top right of picture, you can also see where I’ve began to build the boxing in for the concealed toilet cistern.