But why paying money (the car is out of warranty) if the shocks are working fine and the sound is gone?
 
It looks like it works for the problem you had but it wouldn't work for the monroe inner valve problem on certain shocks .....as that issue dissappear when the dcc is unplugged.
That's exactly the issue I had. When I unplugged the DCC fuse, the sound was gone. When I plugged it back, the sound reappeared. This grease solution fixed it for the momment. We'll see how it goes in time, but they recommended to do it every year.