Thank you for your interest in Septic Scrub. I do not understand your pumper's comments. There have been studies done where all of the bacteria in a tank have been killed using bleach, Lysol, and a caustic drain opener. In each the tank regenerated the same level of bacteria as before the treatment without the addition of any outside bacteria sources. It took between 30 and 72 hours. When did you last have your tank pumped? Was it full? Look at our page on how to care for a septic system. If you have any questions, please do not hestitate to call.