Bleach can oxidize starches, but the reaction is slow and incomplete. Starches swell in water, and the alkaline environment of bleach may even harden certain organic residues, potentially worsening the clog.

Bleach failed to clear any of the simulated clogs. 6. Safety and Plumbing Risks Even if bleach were partially effective, the risks outweigh any potential benefit.

Bleach is a poor degreaser. While it can oxidize some fatty acids, it does not emulsify or saponify them. In contrast, specialized drain cleaners use strong bases (lye) to convert fats into water-soluble soap (saponification). Bleach lacks this saponifying ability. It will simply sit on top of a grease clog due to density differences.