You can get a device called a cobra, it's essentially like rods but thinner and on a reel. Available at builders type hire places.
You can fix the same range of adaptors to the end as you can for drain rods. You can use them to thread ropes through.
You might be able to use one of those spade lugs which folds up as you push, then opens as you drag back, but it's a long shot.
If you get, or make something for the end using say ply wood that fits flush in the pipe you might be able to push the rods further through to the next access point using another set of rods, or the cobra mentioned above.
Might be easier just to get digging.
I have made a winding handle so that as I insert rods I keep rotating them to stop them coming apart...that was after having to dig down 4ft to retrieve a set !