I've had the same problem with the struggle of getting the antenna wire through the tube on ARF's.
Go to your HS and get a 36" length of small diameter piano wire. Add a small trickle of medium CA to the tip of the wire, place the tip of your receiver antenna flat on the glue (try to get about a 1/4" of adhesion) and give it a shot of accelerator. Run the wire through the tube, then run a sharp blade along the piano wire to separate the two and your in business.