It varies by product and airflow. Solid toilet gel stamps often last up to about 12 days per application, while air/odor gels commonly advertise lifespans of about 15–30 days or 30–60 days depending on the formulation and room airflow.

Typical directions: pour the gel into the drain, wait (common label times range from about 7 minutes up to 15–30 minutes, with 15 minutes frequently cited), then flush with hot water. Repeat if necessary per the product instructions.