Sometimes it is necessary to improvise. I needed to run an ethernet cable through a spare buried water pipe 40m long with no drawstring in place. The solution was to get some baler twine (as this was on a farm) and tie the end of it up into a ball that was a snug fit in the pipe. A vacuum cleaner taped to the other end of the pipe soon pulled the twine through. I only needed one cable, but pulled two through just in case. Buried ducts ALWAYS have water in them. John