I cannot speak for anyone else but I have been using additives in my septic system for years and have had good luck.
The enzymes in the septic tank can be killed with chorine bleach, dishwashing soaps and laundry detergent. The enzyme additives help break down the solids into liquids and help keep the soil in the leach field loose.
We have not even had to have our septic tank pumped out yet. We have lived here 19 years.
Greg