Hi Annelie - This is the shower cleaner that we use to help keep grout and tiles clean and minimize the mildew - it works on kitchen grout too. Hope this helps! Hugs, Holly
PS - We have a FREE eBook with recipes for all of my homemade and all-natural cleaners. You can download it here --> https://pinkfortitude.com/thank#GreenClean
Have you tried this? https://www.hometalk.com/33219023/diy-grout-cleaner
I use a mixture of vinegar water. You can read more about how I clean my tiles here - https://chascrazycreations.com/natural-cleaning-with-vinegar/
This is a great post on cleaning grout.
I just spray a diluted bleach solution on the area, let it set a couple of minutes, then wipe it off. It not only gets rid of the "dirt" it kills mold & mildew as well. If it on an up & down area, use gloves to protect your hands, and wipe a cloth that has been dipped in the bleach solution on the grout & let it set. You will see the difference immediately.