Why don't you just go outside and toss a tennis ball around for 30 min a day? The dog will come inside and just nap. If he picks up a dead bird or something, just yell at him, smack him in his nose if necessary. If he has a cage (which he should) put him in there so he knows he did something wrong. If he does it again, yell, smack him and put him in his cage again. Be firm and consistent. I've been around dogs my whole life and not a single person I know has ever used a shock collar to train them. To me it just seems unnecessary, lazy and borderline cruel. Especially with golden retrievers since they are so easy to train... What if your parents shocked you instead of just yelling, spanking and putting you in 'time out' when you did something wrong? You'd probably grow up with a lot of problems...
Consistent, gentle, and repetitive training, along with a reward system (praise / tidbits) works wonders. Good socialization with adults / children / other animals is greatly important. Hitting and yelling is not necessary nor called for. This will often result in a pup which is coy and scared. Shock collars are despicable also. Remember, your dog will do almost anything that you have the time and patience to teach him to do.
So you're saying if your dog is 6 months old and he starts eating rocks in your driveway, it is despicable to yell, "NO! BAD DOG!" in a deep voice and put him in his cage for 30 min? Then the next time you take him out and he doesn't eat rocks, give him a treat and play with him as you're talking in your fun and loving "good doggy" voice. You made me curious now as it appears I have underestimated the common sense of ET dog owners...what worthwhile dog owner doesn't have some kind of reward system? There is a big difference between hitting the dog and smacking his nose. I also said, do that "if necessary." The only time I ever smacked a dogs nose was to pry his mouth open so I could literally get his own shit out of there. If you are abusive to your dog, they will remember it. One time my uncle kicked my dog and my parents told him he wasn't welcome in our house anymore. Some time later, all was forgotten and he started to visit again. My dog would jump in my lap and go crazy barking and growling at him everytime he came over. Even years later, my uncle wouldn't even be in the house yet and my dog would smell him and go nuts.