This has been tired here:
This person actually took off his ruder and did a lot of playing around to come up with a good working system using the galerider drogue.
Note the attachment points in the attached doucment are amidships not to the stern as shown below. This allows the boat to pivot around the keel. When attached as shown in the drawing below the system did not work at all.
By the way, just an f.y.i, here is how you steer with a bucket or drogue.