Dishwashers are designed to clean dishes, utensils, and other kitchenware, not items like toilet brushes. The high temperatures and water jets in dishwashers may not be sufficient to sanitize a toilet brush, which is typically exposed to more resilient bacteria. Additionally, the design of dishwashers does not accommodate the unique shape and material of toilet brushes, potentially leading to inadequate cleaning.

One of the primary concerns with washing a toilet brush in the dishwasher is the risk of cross-contamination. The bacteria and germs from the toilet brush can spread to other items in the dishwasher, including dishes and utensils. This can pose a significant health risk, as these items come into direct contact with food and mouth, potentially leading to illness.

Dishwashers may not effectively clean toilet brushes due to their bristle design and the nature of the contaminants. The water jets may not reach all areas of the brush, leaving behind bacteria and debris. Moreover, the detergent used in dishwashers is not formulated to tackle the specific types of germs found on toilet brushes.