The additives did not harm the systems, nor provide any measurable benefit. The human digestive system is alive with bacteria, and supplies the bacteria that populate the septic system out in the backyard. We don't need to import bacteria, native bacteria grow and expand as needed in the septic system based on the availability of material to nourish them. In fact, imported bacteria may not survive where they are not dominant. Most Health Departments and State Agencies are very cautious and concerned and about chemical additives, because of the possibility of pollution and damage if not properly applied.
Most jurisdictions control such additives.
1998, Department of Soil Science, North Carolina University. Let us get two terms defined. Treatment and Disposal. Treatment means to reduce the contamination level of the sewerage and is expressed as Primary, Secondary and Tertiary. Disposal refers to the dissipation, or elimination of the water contained in sewerage.