Are there any non-surgical treatments for a bochdalek hernia?

No. A bochdalek hernia is a defect in the muscle of the diaphragm. It generally does not close on its own and requires surgical closure. Although the tissue that pokes through into the chest may spontaneously return to its place in the abdomen, the defect is still there.
No. A bochdalek hernia is a congenital hernia or defect of the diaphragm. It always requires surgical closure.