Thank you for your inquiry. Septic Scrub will not in itself dissolve grease. If your drainfield is slow or flooded, then the biomat is almost certainly clogged and anaerobic. Septic Scrub can help return this to aerobic conditions and the aerobic bacteria will digest the grease. If your infiltrators are clogged, how much do you think got through? Is your drainfield flooded or slow? If it is flooded, then it will have to be pumped before Septic Scrub can be added. It can be pumped through the D-box. If it is pumped through the D-box, it is best to let it rest a day or so, so that the water level can go down below the stone. If this is not possible, consider pumping the drainfield through a hole dug in the middle of the drainfield down through the stone to the soil interface. All of the water in the drainfield can be pumped through this hole. If your wish to discuss your situation, please do not hesitate to call me at (888) 352-7226.