I did exactly the same in my ensuite with those bloody hexagon tiles . We do what we do because we are (expletive deleted)ing useless (expletive deleted)
Isn’t bleach , bleach though ??
Bleach works to some extent . But I can scrub 1 quoin face for 25 minutes .
Just imagine …. Me in the street with a bottle of bleach , swearing - like a local alchi . There must be an easier way .
I marine ply in bathrooms on the stud . Whether that’s worth the extra cost compared to osb is debatable. But I sleep better at night not thinking about it