If your not comfortable with leaving the hook in or dont have good success in doing so, then you could always carry around a good pair of wire cutters. Just cut somewhere between the barb and where it is hooked.... then you could just simply slide the hook out back out the other direction. That's what doctor do when someone gets hooked and the barb is inside the flesh. (I know from experience

) I know that some smaller fish may have trouble reswallowing the hook, especially wide gap circle hooks.
Chris