most of the cause jelling of the soilds then when you have flux of incoming water the jelled ball follows the water out in to the drian field yes the tank is cleaner but then your drain field ends up being replaced due to plugged soils. there are many states that will not let you use these items because they cause more problems then helping. using a septic tank for what it was designed for human waste and graywater they work great, start using garbage disposal and washing paint brushes out, plant fert, potting plant in home or mixing for watering house plants and certian meds that people take,ie: heart and kindney, drain cleaners, grease, fats, coffee grounds, diaper wipes, and the likes, condoms, tile cleaners and toilet cleaners, all will have a bad affect on the septic tank.