yes I agree, I don't know who gave you the advice but it is not good advice.
All that I can add is that please don't expect to see results. Don't be dissapointed when the walks don't go well, really they are too young for leashes and I would not use a collar on their neck for a walk. They are young enough that several good romps outside is better than trying a walk at this point. Don't be discouraged that you are not seeing results. They are babies and should still be with their mother and litter mates. It is too bad that many people think that when a mother starts weaning her pups from milk that her job is over, that is very untrue. Good luck. Measure progress in weeks not each day, Soon they will be big behaved dogs, but it is a long road to get there.