LOL, the grout line does get darker if the pee dries, I have a bottle of Clorox ( from Costco) and an old tooth brush, I just let it seat for a while and wipe with a wet mop, or just towel. You can also add vinegar to the water you use to mop your floors, it removes odors, disinfects, and shines , 3 in 1.
Welcome to club!!!
