Hi there, thought I'd leave my 2 cents here, too, after I used a lot of advise from forums like this which massively helped me through our reno works:
I redid our bathroom and fireplace with beautiful, thick, handmade encaustic cement tiles (pigment cover) and used Fila products throughout as recommended (Bert & May). Terrible choice I must say! The pregrout treatment didn't work at all - even after 3 layers (dark grout) and left our fireplace with horrible smeary dirt stains. The sealer on the walls in the bathroom worked fine. On the floor, however, the light-coloured tiles were more porous and even after 6 whopping layers of sealer and weeks of work and drying time, they did not pearl off the water. Cosmetics, soap etc quickly leave stains on light stone so it's essential they are sealed well, especially in a wet room.
We switched to LTP Mattstone Impregnating sealer (interior + exterior use) and the result was instantly perfect. Fila gets good reviews, for us it didn't work at all. I cannot stress enough to buy a small bottle and try these things out. 30 quid if you're redoing an entire bathroom are quickly forgotten if the result is perfect.
Good luck for all you renovators out there!