Police, detection and assistance dogs are not trained with more force than yours. They are trained with better information. Six differences, none of which costs anything, and all of which are missing from almost every household.
The method
Almost everyone else
A marker lands within half a second of the behaviour
'Good boy' two seconds later, by which time he is already standing up
One word, said once, in the same tone
The word repeated four times, louder each time, until it means nothing
The command is never given where it can be ignored
Called across a park, ignored, and called again — teaching that it is optional
One variable raised at a time: distance, duration, or distraction
All three at once, on the first good day, in a field full of dogs
Reward delivered where you want him standing
Reward tossed out in front, which is where he then goes
Sessions of five minutes, three times a day
One session of forty minutes at the weekend, ending in frustration
None of this is a secret. It is simply what gets taught on a handler's course and almost never reaches the person who bought a puppy, because nobody wrote it down in a form that fits twenty minutes a day.