My dogs love this stick when it has peanut butter put into the grooves! The only disadvantage is it is hard to clean debris out of the grooves.
This product is awesome. Our golden is very prone to plaque and yellow teeth, and we have noticed a difference after one day! We put dog toothpaste inside it, and she chews away. The toy is pretty tough too- our second dog normally destroys things in seconds and it's still going strong!