Bleach for pretty much every surface compatible with it. CLR for the shower itself (or a bathroom cleaner specifically for scale and soap scum). Simple Green (or whatever the equivalent is where you’re from) for every thing else. Buy a decent non-scratch scourer (or a couple) as well as some magic erasers to help with any scale that’s resistant to removal. Oh and glass cleaner for the mirror and maybe shower. Nitrile gloves never hurt if you’re dealing with heavy duty chemicals either. Keep the bathroom well ventilated and never mix chemicals.
The same reason countless studios have destroyed successful IPs (like EA). Sure it’s profitable but it could be MORE profitable. Sales were up last year? Cool story, have sales improved over that this year though??