How do you domesticate an animal for 3 months and then undomesticate them?
My father called it a w-rope. It was tied to the legs over the back and was strung threw the yoke and collar to the harness then around the cheeks. If the horse lowered the head to kick the rope would pull the feet out from underneath, and if kicked only one leg it pull another leg out from underneath it. Evidently they could walk though and after a couple days the horse would be domestic.
This is similar to falconry, where (historically, although this is no longer permitted in most areas) an animal can be held long enough to serve and then released before it loses its wild instincts.
You open the gate.