I have a variflo pool pump unit in Phoenix, very dry and hot. All the forum threads say to disassemble the unit because of sand but I am able to get good movement of the flow handle just by putting liquid dish soap around the valve. Clean debris from around the handle thoroughly and place liquid soap around the handle. Slowly and gently rock the arm up and down to avoid breaking the valve. When the valve moves freely up and down, begin to move it gently from side to side. As it begins to move freely from side to side, then move it in circles all the way around. My valve gets so tight I am sure I could easily break it by moving it too fast and forcefully. I think using soap is better than using some kind of oil that may be hard on the parts. Soap can be rinsed off with running water.