[shannonRN]

Vinegar is acetic acid and is just that--acidic. I don't think dilute vinegar would do harm used in this way, but it would make mucous membranes (think eyes, nose, mouth) burn/sting and doesn't it seem a little harsh? I would try straight water first, if you feel this is a necessary step.

I think you need to be careful that you are not reinforcing him for the lunging/biting behavior. If he is successful in getting attention from you in this way, he will continue to do it.