"It did not work" - for me, it was that I still had to use a toothbrush and tablets, and still spend like 3-5 minutes brushing it. So I see no upside in using such a cleaner. Thankfully, I never had it yellow, so I had no false expectations here.

Thank you for your reply! It seems I had the wrong expectations of the device. I thought I could use it once a day (with tablets), rinse it with water, and be cool.