Drano Max Build Up Remover Drain Cleaner, Enzymes & Probiotics Prevents Clogs & Remove Odor-Causing Buildup, Safe for Septic, Toilets & Pipes in Bathroom Drains & Kitchen Sinks, Commercial Line, 60 oz

I had a similar problem. When I researched draino, I learned it can generate intense heat and can damage pipes, especially for certain applications like toilets. I wound up getting an enzyme treatment, specially flagged as safe for toilets and showers. After days of failed attempts with other methods, a single overnight treatment fixed my drain: DranoMaxBuildUpRemoverDrain