LPT Request: how can I make tile grout in the shower/on the floor white again using non chemical items? Also how to keep them white.

In my apartment, the ventilation in the shower room isn’t working properly, so I don’t want to use strong chemical solutions to clean.

I heard somewhere that rinsing the tiles with really hot water would keep them cleaner and the tile would dry quicker, thus preventing the mould growth. Is there any truth to it? Thank you.