Yes, just vinegar mixed 50/50 with water, you can also use citric acid. You will want to disassemble the pump including removing the drive unit from the shaft so the vinegar can get to all places. You might consider our cleaning kit 0220.700, it includes a DVD of instructions for cleaning all pumps and products and all the different brushes and tools for small openings and disassembly. All the brushes are US made of nylon and stainless steel wire. The tools are also US made.