I have tried calling for foxes in Virginia with little affect.
Honestly, I saw way more foxes from a deer stand. I used a Rex Fox Urine cover scent for my walk into my deer stands and fox encounters went through the roof. At least one fox visit each trip.
So after I connected the dots; I tried it for fox hunting specifically. I used a heavily soaked rag on a drag cord and walked into my hunting area. Setting up 20 yards or so from the edge of a field. A fox on the prowl would make a B-Line when they hit the scent trail and come right in to me. Killed a lot of "turkey eaters" that way.
Try it, it might work depending on where and how you hunt. Worst case your out an extra $5.