It depends on the dog's personality, I think. The puppy my mom got when I was 10 was already a snappy bitch, then we played tug with it all the time and it got worse. By the time it was an adult, it would bite you for standing too close to its food dish or for looking at it funny! Not fun.
If it's a very timid dog though, I think it might do some good and teach it assertiveness.