You need to have a relationship with the dog before you.

I keep seeing dogs understand very clearly that certain behaviors they are not supposed to do. There is no negative side effects

If you have not done it before, it can be hard to comprehend that it would work, you will start going down the road of "imagined harm" and all of these other possible scenario that just don't exist and then that keeps folks from actually trying it and unfortunately still stuck with a dog with problems.