Our toilet bowl cleaning tablets contain lemon extract, biological enzymes. It is effective in opening blocked drainage fields and removing biomats. The way to use it is very simple: 1. Take the effervescent tablet and put it in the toilet. 2. Let sit for 10-30 minutes to dissolve completely. 3. Use a toilet brush for basic cleaning, then rinse. And its formula is gentle, it is not easy to damage the glaze of the inner wall of the toilet, and it will not damage the bathroom pipes.