How to clean bathroom shower grout yellow stain?

Paint with chalk paint & seal.

I've heard bar keepers might work I'd research that. Hope it helps

Hi Bob,

Make a paste of baking soda and water then apply it to the grout. Let it sit for a while - even overnight then rinse well. I hope that helps. Wishing you the best.

Hello! Heres some other recommended cleaners

The Best Way to Clean Grout-EVER!!! | Hometalk

https://www.hometalk.com/diy/clean/bathroom/the-best-way-to-clean-grout-ever-2295735?expand_all_questions=1

https://www.hometalk.com/diy/clean/floors/homemade-grout-cleaner-recipe-41693881?expand_all_questions=1

https://www.bobvila.com/articles/cleaning-grout/#.Wi6YzKZOmf0

https://www.hometalk.com/search/posts?filter=clean%20grout

Additionally

Painted Tile Grout Refresh with grout pen

https://www.blesserhouse.com/painted-tile-grout-refresh/

Grout cleaning/ grout removal and replace it

Here’s a Hometalk link for you to consider. Hope this helps

https://www.hometalk.com/diy/clean/bathroom/how-to-clean-grout-and-install-new-grout-that-won-t-stain-23803774

Sound like you need o dig it out and put new and put a silicone sealer over it after

Here is how I clean mine https://chascrazycreations.com/clean-bathroom-natural-products/