A hoofpick often goes too deep into the lateral blasting grooves; The tip of the wire brush can't do that.
The brush of the hoofpick quickly fills with hay; That's not going to happen to you now.
A wire brush even stimulates the frog to become healthier and grow better. In addition, you now really clean the sole well. You can also feel & hear over the white line with the tip of the wire brush whether there is still a stone there, and remove it.
