“The tabs keep the bowl clean with a gentle effervescent reaction. It is amazingly tough on stubborn calcium buildup but that is the magic of KOH I recommend the rubber brush instead of the disgusting bristle brushes we all have been using so far. The only important thing to do is to keep the tablets in a small airtight container, as air moisture can reduce the efficacy of the tablets. The tablets are fragrance-free however, I do add a few drops of peppermint essential oil after the clean. Job done ☑️”