I finally got to use my shower again.
Susan decided that the upstairs shower needed a thorough cleaning. I didn't think it was that bad. But once I saw the finished result after she went through it, I was startled and a bit ashamed. I had let it get far too grungy.
On top of taking a course brush and scrubbing every grout seam in the whole shower, she resealed the grout with a sealer she painted on. It was white so it nicely covered the old grout lines.
It had to dry for 72 hours so I had to use the downstairs shower all week.
It was glorious to get back to my shower space and really enjoy and good clean stall.
I WILL NOT let it get that bad again.