Spritzing Your Dog

Q: Some puppy kindergarten trainers use a squirt bottle to squirt water (with or without additives such as lemon juice, vinegar, Bitter Apple, etc.) to squirt a puppy if it plays too roughly with others. Do you consider this a positive and up-to-date technique? Is this a technique you personally use or endorse? And if not, what would you recommend doing instead, when one pup in class plays too roughly with another?