Has anyone ever used this for their yorkies teeth? Because Mignons mouth is sooo tiny I cannot get my finger in their to brush her teeth and the toothbrush doesnt work good either

my vet recommended this to me as a treat. Both of the yorkies LOVE them as cookies but I was reading the bag and I think it is actually a total diet as well.
Now I am not stupid enough to use it like that because the second I did they would not eat them anymore, but I was wondering if anyone has used this as a dental care plan and how well it worked? Mignon has already had her teeth cleaned once because of retained puppy teeth but I am afraid she might be a plaque builder, I do hope these work!