Last Friday night was the last application of Digesta in our waste pipe cleaning experiment and you may be interested in the results. Following your help and advice I mixed 200ml of water with a wine bottle cap full of Digesta every evening from 10th November and put it down the sink after the last use every night. Maybe it was my imagination but I think I could hear a fizzing sound from the u bend. By the 21st November the sink was running much faster and this morning it was very fast and had a whirlpool. My impression is that the blockage has been removed. Good ol Digesta.