I like to reshare this video at times. My old dog chased deer on sight. You can see in the video it is an instantaneous reaction. I've never used any corrections or special tools for recall and I've successfully called him off deer, bears, porcupine, other dogs, etc. throughout his entire life. There is no shortcut for training recall. It's just consistency, gradually changing variables like environment, not overusing or misusing the recall cue, and finding the right reinforcers.