As per some literature from Dr. Bill Feeman:
"Opting for anesthetic-free dental care is not an appropriate solution to the problem. While anesthetic-free dentals may result in removal of superficial tartar and plaque, the effect is purely cosmetic and does not address the serious medical concerns that occur under the gum line. It is also virtually impossible to thoroughly clean the inner surface of the teeth, so money spent on anesthetic-free dentistry is money wasted."
It's a nice thought, but is not going to treat the issues in the mouth correctly,