I cleaned out the insides of the long W917 Aileron Bellcrank Pushrods. A wad of Scotch-Brite was fixed to the end of a 5 foot rod and spun inside of the tubes with an electric drill. It seemed to be very effective. After rinsing out the residue with Acetone and drying, a fair quantity of primer was poured into one end of each tube with the other ends closed up with balloons and tape. The open ends were sealed and the tubes were tipped and rotated for a while in an effort to distribute the primer evenly. I left the tubes hanging overnight to drain out the excess primer. I'll wait two days to be sure the primer is completely dried before continuing assembly of the Pushrods.