Tried once at Powell River, on the BC Sunshine coast. Very thick rainforest, no coyotes...predators are black bears, cougars, and wolves. A friends domestic animal died, so he moved it to a remote logging slash and set up a trailcam. Wolves ate it.
I tried a foxpro with no success. Even though, where i set up was "open", that was relative to that country. Lots of crows and ravens attended. I would think given the nature of wolf pack ranges they could have been either km's away or just hidden in the lush growth.