Dental cleaning for Dog question

I have a 7 year old Golden Retriever and 13 year old mini-Aussie/Border Collie and am considering dental cleaning options.  Ideally would like to do a thorough one under anesthesia, but I am nervous about the risks of anesthesia and am wondering what the statistics are. In addition, there is a non-anesthetic service offered by a local company owned by a veterinarian. I know some veterinarians frown upon this because they usually aren't done by veterinary clinics, but this one is done under the supervision of a licensed veterinarian.  Given these two options, what would compel a dog owner to go the route of anesthesia when that has a risk of death and the other has zero risk of death?  I'm open to both.

Hello!  This is a good question, but with a very simple answer.   When you go to the dentists for a scale and polish, this is done with you awake.  You hold your mouth open on the dentists chair - which makes a lot of humans feel quite vulnerable - while the dentist carefully works around each tooth, systematically covering every surface with the scaler as necessary and then with the polisher.  Sometimes, you might have a sensitive spot that causes a tweak of pain - you move your head slightly, or flinch away, and the dentist pauses and then perhaps explores the tooth when you're ready, or they come back later with some local anaesthetic.  My dentist once literally used a 'gag' to prevent me from unexpectedly biting her finger or the equipment during a procedure.  Now.  Imagine that you are a dog.  I have never met a dog that opens its mouth on command and holds it open and still, at the correct angle for the dentist to scale and polish every surface of every tooth.  If they have a tender spot, they do not flinch away gently to warn the person holding the scaler.  Furthermore, if there is fluid involved, the canine patient cannot avoid swallowing / spit it out at the appropriate moment and, with the animal conscious, the vet cannot pack the throat to protect the airway.  Furthermore, without an anaesthetic, if the canine patient is unexpectedly hurt (eg a cavity is found), they are likely to make a big movement and could damage their mouth on the heavy scaling implement inside it.  Another point is that in order to proprly inspect a tooth fr such cavities, a vet will have to poke a probe - a slim metal stick - into the gap between the gum and the tooth, right the way around.  I do not understand how this can be done safely or reliably done without an anaesthetic.  Obviously vets would avoid using anaesthesia if it were possible.  Purely from a financial standpoint it would be preferable because we could avoid the equipment and time outlay involved in correctly supervising and anaesthetic, let alone reducing the small patient risk.  The reason vets anaesthetise our patients, is to ensure that the job is done correctly and safely.  I understand what this company is offering, but it is not the same serice and if the resposible veterinary surgeon is advertising it as such in the UK, I would be very concerned.

Sorry:  I do not understand what this company is offering (to do condcious), but it is not the same service and if the responsible veterinary surgeon is advertising it as such in the UK, then I would be very concerned.