It is important to NOT direct the dog’s attention to the whiskers. The whiskers are targets for YOU … not for the dog. The dog should simply be following the path you are drawing. If possible, a spray paint or stick-on dot would be better as it is far more subtle and the dog is less likely to focus on it.
Your goal throughout these exercises is for the cleanest and tightest lines around the course. Clean lines come from steady and clear handler path … tight wraps or turns are the result of excellent timing. The wider the dog goes around a dot or whisker, the later you are … if the dog “short-cuts” a point, then you cued too soon.