Elite dog training?

Would you allow your dog to go to one of the trainings where they keep them over time and bring you in to train with them at the end?
I’m hesitant and just curious what other pet owners think of them? Do you think they’d abuse my dog while she’s away from me? Because I’m worried for that, however I’ve tried basic training and it hardly helped. She needs more one on one training and unfortunately I don’t know how, I let her get away with everything and she’s smart and controls me because of that.
If you have a German shepherd do you have any tips on their behaviors?