Internal coil & system cleaner. EndoFlush is an internal system cleaner ideal for use after a burnout or retrofit. Its low viscosity allows it to be circulated freely around a system to remove contaminants and physical debris, using a flushing pump. On contact, EndoFlush will break down all carbon, tar, oil and sludge deposits. These contaminants are flushed out of the system, leaving internal surfaces clean and ready for re-commissioning. EndoFlush is CFC-free and is not a regulated substance.