Lets see what showers look like when Roberto and I turn up to do some demolition.
Most of the mild I find is in the walls. Most of the smell comes from there. Look at these photos....
Here you see a shower demo'd and it's clear the water has wicked up the drywall and that the drywall is full covered in mild. Here is a good thing to know. The paper layer on both the front and back side of drywall is used by mild as a food source. Another interesting thing to know is cement board has no food source for mold.
Now in this photo you see more water damage - clearly the water migrating in around the fixtures and tub fillers. Wrong setting materials are used i.e. Matic and this shower is another drwall mold feast.
As you can see by this picture the use of Green Drywall helps so much with the problem.... NOT