Don't have any great ideas how to tether the Swallow Bruce but I do have an inexpensive radio controlled Vac-U-Boat tug with about ten foot of fishing line and a bobber that I use as a rescue boat (Jim Dandy to the rescue!). Do a couple of circles around the errant boat and you're ready for the pull back to safety.
I've used a similar technique to Larry's with some success, but also a couple of notable failures due to situations specific to the pond I was "stuck" in. It also can be damaging to the boat to sail it in a swimming pool, if it rams the far wall before you get there to ward it off, and not everybody is going to be friendly to having a trace of steam oil show up in the pool, so you may wish to be extra careful about that possibility.
Perhaps the best situation is to run it in a smallish pond that you can easily walk around within the time it would take for your Swallow to reach the other side when straight running, but still running in a circle along a shore parallel to the wind in a small pond is likely your best scenario.